Back to EveryPatent.com
United States Patent |
5,632,746
|
Middleman
,   et al.
|
May 27, 1997
|
Device or apparatus for manipulating matter
Abstract
The present invention provides a device or apparatus for manipulating
matter in a confined or inaccessible space, comprising manipulator means
at least partly constructed of one or more bent or twisted elongate shape
memory alloy members having pseudoelasticity at the intended manipulation
temperature, and a hollow housing (preferably of elongate tubular form) or
cannula capable of holding at least the shape memory alloy member(s) in a
relatively straightened state, and actuating means for extending the shape
memory alloy member(s) from the housing to manipulate matter within the
said space and for withdrawing the shape memory alloy member(s) into the
housing, the arrangement being such that the shape-memory alloy member(s)
bend(s) or twist(s) pseudoelastically in a lateral or helical sense to
manipulate the matter on extending from the housing at the said
manipulation temperature, and become(s) relatively straightened on
withdrawal into the housing at the said temperature.
Inventors:
|
Middleman; Lee M. (Portola Valley, CA);
Pyka; Walter R. (Redwood City, CA);
Buhler; Michael (St. Rebe, FL);
Poncet; Philippe (Fremont, CA);
van Dyk; Karl (Fremont, CA);
Jervis; James E. (Atherton, CA);
Zadno; Reza (Newark, CA)
|
Assignee:
|
Medtronic, Inc. (Minneapolis, MN)
|
Appl. No.:
|
843775 |
Filed:
|
February 28, 1992 |
Current U.S. Class: |
606/78; 606/170; 606/174 |
Intern'l Class: |
A61B 017/56 |
Field of Search: |
606/78,170,174
|
References Cited
U.S. Patent Documents
4084594 | Apr., 1978 | Mosior | 606/174.
|
4522206 | Jun., 1985 | Whipple et al. | 606/174.
|
4590936 | May., 1986 | Straub et al. | 606/174.
|
4919133 | Apr., 1990 | Chiang | 606/170.
|
5133721 | Jul., 1992 | Angulo | 606/78.
|
5133727 | Jul., 1992 | Bales et al. | 606/170.
|
5188111 | Feb., 1993 | Yates et al. | 606/78.
|
5190546 | Mar., 1993 | Jervis | 606/78.
|
5192298 | Mar., 1993 | Smith et al. | 606/174.
|
Other References
"An Engineer's Perspective of Pseudoelasticity", by T.W. Duerig and R.
Zadno, Engineering Aspects of Shape Memory Alloys, pp. 369-393.
|
Primary Examiner: Hilten; John S.
Parent Case Text
This application is a continuation-in-pad application of U.S. applications
Ser. Nos. 07/774,016 filed Oct. 9, 1991 now U.S. Pat. No. 5,486,5;
07/594,768 filed Oct. 9, 1990 now abandoned; 07/608,117 filed Nov. 1, 1990
now abandoned; 07/608,121 filed Nov. 1, 1990 now abandoned 07/594,769
filed Oct. 9, 1990 now abandoned; 07/608,121 filed Nov. 11, 1990 now
abandoned; 07/594,871 filed Oct. 9, 1990 now abandoned; 07/594,896 filed
Oct. 9, 1990 now abandoned; 07/594,874 filed Oct. 9, 1990 now abandoned;
07/594,873 filed Oct. 9, 1990 now abandoned; 07/656,651 filed Feb. 15,
1991 now abandoned; and 07/631,809 filed Dec. 21, 1990, now U.S. Pat. No.
5,509,923 which in turn is a continuation-in-part of 07/394,463 filed Aug.
16, 1989, now abandoned. The entire disclosures of these applications are
hereby incorporated by reference for all purposes.
Claims
What is claimed is:
1. A device having a distal end and a proximal end for surgical
manipulation of matter within a living body comprising:
(i) manipulator means having a distal end, said distal end at least partly
constructed of at least one bent or twisted elongate metallic member
having pseudoelasticity at a intended manipulation temperature,
(ii) a hollow housing or cannula which initially holds said distal end in a
relatively straightened state, and
(iii) a proximal end and actuating means operable from said proximal end of
the device for extending the distal end from the housing to manipulate
matter within a living body and for withdrawing the distal end into the
housing, wherein the distal end is deformable to bend or twist
pseudoelastically in a lateral or helical sense so as to manipulate the
matter on extension from the housing at the manipulation temperature, and
said distal end becoming relatively straightened on withdrawal into the
housing at the said temperature.
2. Apparatus according to claim 1, which is a surgical instrument
comprising handle means, coupled to at least one of said cannula or
housing and said at least one member, said means for manually inserting
said member through said cannula or housing to distally extend said distal
segment from a bore of said cannula or housing, and for withdrawing said
distal segment into the bore.
3. Apparatus according to claim 1, wherein said proximal end and said
distal end are of unitary construction.
4. Apparatus according to claim 1, wherein said distal end structure and
said at least one member are of unitary construction.
5. Apparatus according to claim 1, wherein said distal end structure has a
substantially blunted shape, and has a lateral dimension substantially
equal to a lateral dimension of said cannula or housing, and is coupled to
a distal end of said at least one member such that a curved surface of
said distal end structure is distal facing.
6. Apparatus according to claim 5, wherein said distal end structure
comprises a non-elastic structure separate from, and coupled to, said at
least one member.
7. Apparatus according to claim 1, wherein said distal end structure is a
pointed tip of said distal end.
8. Apparatus according to claim 1 wherein said at least one member is
disposed within said cannula or housing and oriented such that said
elastic distal end exits said cannula or housing in a predetermined
lateral orientation; and the apparatus further comprises means for
indicating said predetermined lateral orientation.
9. Apparatus according to claim 8, further comprising means for preventing
said at least one member from rotating within said cannula or housing.
10. An apparatus according to claim 1, wherein said distal segment is
composed of a nickel-titanium based pseudoelastic alloy.
11. An apparatus according to claim 1, wherein at least a portion of the
distal end is composed of a pseudoelastic ahoy which assumes a first shape
h a substantially austenitic phase when extended from the housing or
cannula, and assumes a second shape containing more martensite phase when
withdrawn into the housing or cannula.
12. An apparatus according to claim 1 including means for indicating the
orientation of the pseudoelastically deformable distal end when extended
from the housing or cannula.
13. The device as defined in claim 1 wherein said manipulation is
dissection.
14. The device as defined in claim 1 wherein the pseudoelasticity is linear
pseudoelasticity.
15. A remotely operated surgical device comprising
(a) a substantially linear housing having a distal deployment opening;
(b) a curved pseudoelastic blade, said blade constrainable in a relatively
straightened shape within the housing; and
(c) remote means for projecting and retracting the pseudoelastic blade
relative to the distal deployment opening between a first position wherein
the pseudoelastic blade is constrained in a relatively straightened shape
within the housing, and a second position wherein the psendoelastic blade
is not constrained by the housing and assumes a relatively curved shape.
16. A device according to claim 15 which comprises an endoscopic device, a
catheter, or a laparoscopic device.
17. A device according to claim 15 wherein the pseudoelastic blade
comprises at least one cutting edge.
18. A device according to claim 17 wherein said at least one cutting edge
is constructed of a material which is different from that of the
pseudoelastic blade.
19. An instrument device comprising
(a) a distal bladed element having a first pivoted blade, and a second
opposing blade;
(b) an elastically deformable stem connected to the bladed element;
(c) a proximal blade actuator means for causing pivotal motion of the
pivotable blade; and
(d) a stem deformation control means for controlling the deformation of the
elastically deformable stem.
20. A device according to claim 19 wherein the elastically deformable stem
comprises an elastic member which is substantially straight when it is
constrained, and assumes a bent or curved shape when it is unconstrained;
and the stem deformation control means comprises a longitudinally slidable
substantially straight constraining member.
21. A device according to claim 20, comprising an elongate housing and
wherein the elastic member is moveable between a first position wherein
the elastic member is constrained within the housing, and a second
position wherein the elastic member is deployed from the housing and
assumes an unconstrained shape.
22. A device according to claim 21 wherein said elongate housing comprises
a rigid elongate tube.
23. A device according to claim 19 further comprising an elongate housing
including a flexible polymeric tube.
24. A device according to claims 19 wherein at least one of the first blade
and the second blade includes a grasping surface which can be used to
grasp an object, or wherein at least one of the first blade and the second
blade includes a cutting edge which can be used to cut an object.
25. A device according to claim 19, wherein the first blade is moveable
between a closed position wherein the axes of the blades are substantially
parallel, and an open position, wherein the axes of the blades are
deflected from the parallel.
26. A device according to claim 19 in which at least the bladed element is
readily removable from the device and wherein said bladed element is
capable of integrating with the blade actuator means, and wherein the
elastically deformable stem is capable of integrating with the stem
deformation control means.
27. An apparatus according to claim 19 wherein the elastically deformable
distal stem is composed of pseudoelastic material or superelastic material
under the intended conditions of use.
28. A device for dissecting an object comprising at least two elongate
elements, positioned alongside one another, each having a body portion and
an end portion:
i. means for splaying the end portions apart from one another when free of
transverse constraint to dissect the object from surrounding material; and
ii. said end portions being movable toward one another,
wherein a portion of at least one of the elements is formed from a
pseudoelastic material.
29. A device for gasping or cutting an object comprising at least two
elongate elements, positioned alongside one another, each having a body
portion and an end portion:
i. means for splaying the end portions apart from one another when free of
transverse constraint and presenting grasping or cutting surfaces to an
object to be grasped or cut that is placed between them; and
ii. said end portions being movable toward one another to grasp or cut said
object;
wherein a portion of at least one of the elements is formed from a
pseudoelastic material.
30. A device for grasping or cutting an object comprising:
a. at least two elongate elements, positioned alongside one another, each
having a body portion and an end portion:
i. means for splaying the end portions apart from one another when free of
transverse constraint and presenting grasping or cutting surfaces to an
object to be grasped or cut that is placed between them; and
ii. said end portions being movable towards one another to grasp or cut
said object; and
b. actuating means for said elongate elements;
wherein a portion of at least one of the elements and/or said actuating
means is formed from a pseudoelastic material.
31. A device for grasping or cutting an object comprising:
a. a hollow elongate component; and
b. at least two elongate elements, at least part of which are positioned
within said component, said elements being positioned alongside one
another, each having a body portion and an end portion:
i. means for slaying the end portions apart from one another when free of
transverse constraint and presenting grasping or cutting surfaces to an
object to be grasped or cut that is placed between them; and
ii. said end notions being movable towards one another to grasp or cut said
object;
wherein the elements and the component are longitudinally slideable
relative to one another so that at least a portion of the elements can be
slid into and out of said component and wherein a portion of at least one
of the elements is formed from a pseudoelastic material.
32. A device for dissecting an object comprising:
a. at least two elongate elements, positioned alongside one another, each
having a body portion and an end portion:
i. means for splaying the end portions apart from one another when free of
transverse constraint for dissecting the object from surrounding material;
and
ii. said end portions being movable toward one another; and
b. actuating means for said elongate elements;
wherein a portion of at least one of the elements and/or said actuating
means is formed from a pseudoelastic material.
33. A device as claimed in claim 29, claim 30, or claim 31, which further
comprises at least one of (i) a cutting edge of a material other than a
pseudoelastic alloy, and (ii) a grasping surface.
34. A device for dissecting an object comprising:
a. a hollow elongate component; and
b. at least two elongate elements, at least part of which are positioned
within said component, said elements being positioned alongside one
another, each having a body portion and an end portion:
i. means for splaying the end portions apart from one another when free of
transverse constraint to dissect said object from surrounding material;
and
ii. said end portions being movable toward one another;
wherein the elements and the component are longitudinally slideable
relative to one another so that at least a portion of the elements can be
slid into and out of said component and wherein a portion of at least one
of the elements is formed from a pseudoelastic material.
35. A device as claimed in claim 34 or claim 31, wherein one or both of (i)
said elongate elements and (ii) the end portions thereof splay apart when
they are not deformed within the hollow component and said elongate
elements are moved toward one another when they are drawn into the hollow
component, or when the hollow component is passed over said elongate
elements.
36. A device as claimed in claim 34 or claim 31, wherein the end portion of
at least one of said elements is formed from a pseudoelastic material and
is curved at a predetermined angle with respect to the hollow component
when said end portion is extruded from the component.
37. A device according to claim 34 or 31 which includes an actuating means
which (i) actuates a linkage to splay apart the elongate elements and (ii)
extrudes the elongate elements from, and withdraws the elongate elements
into, the component.
38. A device as claimed in claim 34 or 31, wherein each elongate member is
attached to a longitudinal member and which can be rotated relative to
each other.
39. A device as claimed in claim 28, claim 29, claim 32, claim 30, claim
34, or claim 31, in which the end portions of the elements are pivotally
connected to one another towards their free ends.
40. A device as claimed in claim 28, claim 29, claim 32, claim 30, claim 34
or claim 31, which includes a flexible component that extends between the
end portions of the elements so as, together with the end portions of the
elements, to form a closed loop.
41. A device as claimed in claim 28, claim 29, claim 32, claim 30, claim
34, or claim 31, in which the body portions of the elements are attached
to one another, so that they are moved together in the longitudinal
direction.
42. A method of dissecting an object from surrounding material, comprising:
A. providing a device which comprises at least two elongate elements,
positioned alongside one another, each having a body portion and an end
portion, the end portions of the elements splaying apart from one another
when free of transverse constraint to dissect said object from surrounding
material; and wherein a portion of at least one of the elements is formed
from a pseudoelastic material;
B. positioning end portions adjacent the object; and
C. causing said end portions to splay apart so as to dissect said object
from surrounding material.
43. A method of dissecting an object from surrounding material, which
comprises:
A. providing a device which comprises
a. at least two elongate elements, positioned alongside one another, each
having a body portion and an end portion, the end portions of the elements
slaying apart from one another when free of transverse constraint; and
b. actuating means for said end portions; wherein a portion of at least one
of the elements and/or said actuating means is formed from a pseudoelastic
material;
B. positioning said end portions adjacent said object; and
C. causing said end portions to splay apart so as to dissect said object
from surrounding material.
44. A method of dissecting an object from surrounding material, comprising;
A. providing a device which comprises:
a. a hollow elongate component; and
b. at least two elongate elements, at least part of which are positioned
within said component, said elements being positioned alongside one
another, each having a body portion and an end portion, the end portions
of the elements slaying apart from one another when free of transverse
constraint; and
wherein the elements and the component are longitudinally slideable
relative to one another so that at least a portion of the elements can be
slid into and out of said component and wherein at least a portion of at
least one of the elements is formed from a pseudoelastic material;
B. positioning said end portions adjacent said object; and
C. causing said end portions to splay apart so as to dissect said object
from surrounding material.
45. A method of grasping or cutting an object, comprising:
A. providing a device which comprises:
a. at least two elongate elements, positioned alongside one another, each
having a body portion and an end portion, the end portions of the
elements:
i. means for splaying the end portions apart from one another when free of
transverse constraint and presenting gasping or cutting surfaces to an
object to be grasped or cut that is placed between them; and
ii. said end portions being movable toward one another to grasp or cut said
object;
wherein at least a portion of at least one of the elements is formed from a
pseudoelastic material;
B. positioning the object between the splayed apart end portions of the
elements; and
C. causing said end portions to move toward one another so as to grasp or
cut said object.
46. A method of grasping or cutting at, object, comprising:
A. providing a device which comprises:
a. at least two elongate elements, positioned alongside one another, each
having a body portion and an end portion, the end portions of the
elements:
i. means for splaying the end portions apart from one another when free of
transverse constraint and presenting grasping or cutting surfaces to an
object to be grasped or cut that is placed between them; and
ii. said end portions being movable toward one another to grasp or cut said
object; and
b. actuating means for said end portions;
wherein at least a portion of at least one of the elements and/or said
actuating means is formed from a pseudoelastic material;
B. positioning said object between the splayed apart end portions of the
elements; and
C. causing said end portions to move toward one another so as to gasp or
cut said object.
47. A method of grasping or cutting an object, comprising:
A. providing a device which comprises:
a. a hollow elongate component; and
b. at least two elongate elements, at least part of which are positioned
within said component, said elements being positioned alongside one
another, each having a body portion and an end portion:
i. means for splaying the end portions apart from one another when free of
transverse constraint and presenting grasping or cutting surfaces to an
object to be grasped or cut that is placed between them; and
ii. said end portions being movable toward one another to grasp or cut said
object;
wherein the elements and the component axe longitudinally slideable
relative to one another so that at least a portion of the elements can be
slid into and out of said component and where, at least a portion of at
least one of the elements is formed from a pseudoelastic material;
B. positioning said object between the splayed apart end portions of the
elements; and
C. causing said end portions to move toward one another so as to grasp or
cut said object.
Description
BACKGROUND OF THE INVENTION
This invention relates to a device or apparatus for manipulating matter
within a confined or inaccessible space, especially during surgery in a
living body.
Matter may be manipulated in such circumstances in various ways, for
example by application of a ligature, by suturing, by cutting with a knife
or scissor action, or by capture and retrieval in devices such as screens,
baskets, barriers, pouches, or retractors. Such manipulation may be
difficult when operating in the confined space of a very deep wound or
through a small arthroscopic or other endoscopic incision or body
aperture.
Many forms of apparatus for performing surgical operations have been
proposed previously using flexible steel wires which spring apart when
extended from the distal end of a tube and which can be brought together
again on withdrawal back into the tube. Examples of such known devices may
be seen in U.S. Pat. Nos. 2,114,695, 2,137,710, 2,670,519, 3,404,677,
4,174,715, 4,190,042, 4,222,380, 4,249,533, 4,347,846, 4,655,219,
4,691,705, 4,741,335, 4,768,505 and 4,909,789. However, these devices may
not be completely satisfactory for various reasons, especially after
repeated use or long storage which may fatigue the materials used.
Attempts have been made to use shape memory metals in surgical apparatus,
but these suffer from inconvenience and from the risk of damage to living
tissues resulting from the need either to cool the memory metal while
positioning it in the body so that body heat thereafter actuates the shape
memory effect, or to heat the metal above body temperature to actuate it
after positioning. Examples of such attempts are described in U.S. Pat.
Nos. 4,509,517, 3,868,956 and 4,425,908.
The present invention uses pseudoelastic materials, preferably
pseudoelastic shape memory alloys, which bend pseudoelastically to perform
manipulations which may be difficult or impossible to achieve reliably
with previously known devices. Pseudoelastic alloys have previously been
described for non-manipulative devices such as lesion marker probes, bone
anchors, heart valves, intrauterine devices, dental arch wire, coil stents
and filters, as described in U.S. Pat. Nos. 4,665,906 (Jervis), 4,616,656
(Nicholson), 4,898,156 (Gatturna), 4,899,743 (Nicholson), and 4,946,468
(Li). In one case, U.S. Pat. No. 4,926,860 (Stice) describes a straight
suturing needle made of such alloy which ensures the needle emerges
straight after being inserted through a curved cannula. None of these
known uses in any way suggests the present ingenious use of the power of
pseudoelastic bending on extending a pseudoelastic manipulator means from
a cannula to perform manipulations in difficult locations.
SUMMARY OF THE INVENTION
The present invention accordingly provides a device or apparatus for
manipulating matter in a confined or inaccessible space, comprising
(i) manipulator means at least partly constructed of one or more bent or
twisted elongate shape memory alloy members having pseudoelasticity at the
intended manipulation temperature, and
(ii) a hollow housing (preferably of elongate tubular form) or cannula
capable of holding at least the shape memory alloy member(s) in a
relatively straightened state, and
(iii) actuating means for extending the shape memory alloy member(s) from
the housing to manipulate matter within the said space and for withdrawing
the shape memory alloy member(s) into the housing, the arrangement being
such that the shape-memory alloy member(s) bend(s) or twist(s)
pseudoelastically in a lateral or helical sense to manipulate the matter
on extending from the housing at the said manipulation temperature, and
become(s) relatively straightened on withdrawal into the housing at the
said temperature.
DETAILED DESCRIPTION OF THE INVENTION
Preferably the invention provides such a device or apparatus which is of
elongate form for surgical manipulation of matter within a living body,
and which has the manipulator means at its distal end with the shape
memory alloy member(s) having pseudoelasticity at the temperature to be
encountered within that body, and wherein the actuating means is operable
from the proximal end of the device.
Various forms of device or apparatus will now be described independently,
it being understood that all may be inventive in themselves, although all
are preferably within the scope of at least the first (more preferably
both) of the two immediately preceding paragraphs. Non-surgical uses may
be appropriate for some forms.
Any elastic material may be used in some of the embodiments of this
invention, but it is generally preferred to use a pseudoelastic material.
Many different materials exhibit pseudoelasticity and can be used in any
embodiment of this invention. It is preferred to use a pseudoelastic shape
memory alloy.
The term "elastic material" is used herein to mean a material that has
spring-like properties, that is, it is capable of being deformed by an
applied stress and then springing back, or recovering, to or toward its
original unstressed shape or configuration when the stress is removed. The
elastic material is preferably highly elastic. The material can be
polymeric or metallic, or a combination of both. The use of metals, such
as shape memory alloys, is preferred. Shape memory alloys that exhibit
pseudoelasticity, in particular superelasticity, are especially preferred.
The elastic materials herein exhibit greater than 1% elastic deformation,
more generally greater than 2% elastic deformation. Preferably, the
elastic materials herein exhibit greater than 4% elastic deformation, more
preferably greater than 6% elastic deformation.
Preferably, the elastic member is at least partially formed from a
pseudoelastic material, such as a shape memory alloy that exhibits
pseudoelasticity. Shape memory alloys which exhibit superelasticity (also
referred to in the literature as non-linear pseudoelasticity), are
especially preferred.
U.S. Pat. No. 4,935,068 to Duerig, which is commonly assigned with the
present application and incorporated herein by reference, teaches the
fundamental principles of shape memory alloys. Some alloys which are
capable of transforming between martensitic and austenitic phases are able
to exhibit a shape memory effect. The transformation between phases may be
caused by a change in temperature. For example, a shape memory alloy in
the martensitic phase will begin to transform to the austenitic phase when
its temperature rises above A.sub.s and the transformation will be
complete when the temperature rises above A.sub.f. The forward
transformation will begin when the temperature drops below M.sub.s and
will be complete when the temperature drops below M.sub.f. The
temperatures M.sub.s, M.sub.f, A.sub.s, and A.sub.f define the thermal
transformation hysteresis loop of the shape memory alloy.
Under certain conditions, shape memory alloys exhibit pseudoelasticity,
which does not rely on temperature change in order to accomplish shape
change. A pseudoelastic alloy is capable of being elastically deformed far
beyond the elastic limits of conventional metals.
The property of pseudoelasticity of certain shape memory alloys, which
preferably is used in the devices of this invention, is the subject of a
paper entitled "An Engineer's Perspective of Pseudoelasticity", by T. W.
Duerig and R. Zadno, published in Engineering Aspects of Shape Memory
Alloys, page 380, T. W. Duerig, K. Melton, D. Stoeckel, and M. Wayman,
editors, Butterworth Publishers, 1990 (proceedings of a conference
entitled "Engineering Aspects of Shape Memory Alloys", held in Lansing,
Mich. in August 1988). As discussed in the paper, the disclosure of which
is incorporated herein by reference, certain alloys are capable of
exhibiting pseudoelasticity of two types.
"Superelasticity" arises in appropriately treated alloys while they are in
their austenitic phase at a temperature which is greater than A.sub.s and
less than M.sub.d (A.sub.s is the temperature at which, when a shape
memory alloy in its martensitic phase is heated, the transformation to the
austenitic phase begins, and M.sub.d is the maximum temperature at which
the transformation to the martensitic phase can be induced by the
application of stress). Superelasticity can be achieved when the alloy is
annealed at a temperature which is less than the temperature at which the
alloy is fully recrystallized. Alternative methods of creating
superelasticity in shape memory alloys, such as solution treating and
aging, or alloying, are also discussed in "An Engineers Perspective of
Pseudoelasticity", referenced above. An article may be provided with a
desired configuration by holding it in that configuration during
annealing, or during solution treatment and aging. An article formed from
an alloy which exhibits superelasticity can be deformed substantially
reversibly by 11% or more. In contrast, "linear pseudoelasticity", is
believed not to be accompanied by a phase change. It is exhibited by shape
memory alloys which have been cold worked or irradiated to stabilize the
martensite, but have not been annealed in the manner discussed above. An
article formed from an alloy which exhibits linear pseudoelasticity can be
deformed substantially reversibly by 4% or more. The treatment of shape
memory alloys to enhance their pseudoelastic properties is also discussed
in above-mentioned U.S. Pat. No. 4,935,068 to Duerig, incorporated herein
by reference.
While the alloy that is used in the devices of this invention may exhibit
either linear pseudoelasticity or superelasticity (which is sometimes
referred to as non-linear pseudoelasticity), or pseudoelasticity of an
intermediate type, it is generally preferred that it exhibit
superelasticity because of the large amount of deformation that is
available without the onset of plasticity. U.S. Pat. No. 4,665,906 to
Jervis, which is commonly assigned with the present application and is
incorporated herein by reference, teaches the use of pseudoelastic shape
memory alloys in medical devices.
The pseudoelastic material will be selected according to the
characteristics desired of the article. When a shape memory alloy is used,
it is preferably a nickel titanium based alloy, which may include
additional elements which might affect the yield strength that is
available from the alloy or the temperature at which particular desired
pseudoelastic characteristics are obtained. For example, the alloy may be
a binary alloy consisting essentially of nickel and titanium, for example
50.8 atomic percent nickel and 49.2 atomic percent titanium, or it may
include a quantity of a third element such as copper, cobalt, vanadium,
chromium or iron. Alloys consisting essentially of nickel, titanium and
vanadium, such as disclosed in U.S. Pat. No. 4,505,767, the disclosure of
which is incorporated herein by reference, are preferred for some
applications, particularly since they can also exhibit superelastic
properties at or around body temperatures, and because they are stiffer
and/or can store more elastic energy. Copper based alloys may also be
used, for example alloys consisting essentially of copper, aluminum and
nickel; copper, aluminum and zinc; and copper and zinc.
An article exhibiting superelasticity can be substantially reversibly
deformed, by as much as eleven percent or more. For example, a 1.00 meter
length of superelastic wire may be stretched to 1.11 meters in length,
wherein its alloy will undergo a phase change to at least a partially more
martensitic phase known as stress-induced-martensite. Upon release of the
stress, the wire will return substantially to its 1.00 meter length, and
its alloy will, correspondingly, return at least substantially toward its
more austenitic phase. By way of contrast, a similar wire of spring steel
or other conventional metal may only be elastically stretched
approximately one percent, or to 1.01 meter in length. Any further
stretching of the conventional wire, if not resulting in actual breakage
of the wire, will result in a non-elastic (plastic) transformation such
that, upon relief of the stress, the wire will not return to its original
length. Linear pseudoelastic and superelastic materials may also be bent,
twisted, and compressed, rather than stretched, to a far greater degree
than conventional metals.
It is believed that the superelastic property is achieved by phase
transformation within the alloy, rather than by the dislocation movements
which occur during the plastic deformation of ordinary metals. A
superelastic material may be deformed and released thousands of times,
without being subject to breakage due to the metal fatigue which limits
the number of deformation cycles which an ordinary metal may undergo
without failure.
Shape memory alloys have a special feature which is beneficial for certain
of the embodiments of this invention. As a superelastic shape memory alloy
is increasingly deformed from its unconstrained shape, some of its
austenitic phase changes into stress-induced-martensite. The stress/strain
curve presents a plateau during this phase change. This means that while
the alloy undergoes this phase change, it can deform greatly with only
minimal increases in loading. Therefore, elements comprising superelastic
shape memory alloys have a built-in safety feature. These elements can be
designed (using appropriately treated alloys and appropriate dimensions)
such that when they are loaded beyond a certain amount, the elements will
tend to deform with a concomitant austenite to stress-induced-martensite
phase change, instead of merely presenting a greater resistance or force
with limited deformation to the load, which is seen with conventional
metals.
Just as the stress strain curves of shape memory alloys present a plateau
upon loading, they also present a plateau in the stress strain curve upon
unloading. Unloading occurs when an element made of superelastic shape
memory alloy is permitted to revert from a significantly deformed shape
toward its original unstressed shape. Because of the plateau, such an
element can maintain an almost constant force during much of the unloading
cycle until just before it is completely unloaded.
One form of the present invention provides a surgical instrument which
enables the passage of a ligature around a bone, blood vessel, or other
such body member, or the grasping of such a body member, without requiring
the surgical instrument to be swept over a wide angle of motion. The
apparatus includes a cannula and, within the cannula, a member which is at
least partly constructed of an elastic material, preferably a
pseudoelastic material and most preferably a pseudoelastic shape memory
alloy, such as those disclosed in U.S. Pat. No. 4,665,906 to Jervis, dated
May 19, 1987, and U.S. Pat. No. 4,505,767 to Quin, dated Mar. 19, 1985,
which are preferred for all forms of this invention and which are
incorporated herein by reference.
Although the following detailed description and the accompanying Figures
illustrate the cannula as having a straight shape, and the elastic member
as being held therein in a straightened configuration, it will be
understood that the cannula may advantageously be formed with any
desirable shape, such as an arc, and that the elastic member may take on
any desirable shape upon extrusion from the cannula.
The straight cannula and curved elastic members are used as examples, only,
and should not be interpreted to limit the scope of this invention. It
will also be understood that although the cannula is discussed as being
fairly rigid, it may be formed of a plastically deformable material, which
will allow the surgeon to shape the instrument to any required
configuration. The instrument may also be flexible to be used within the
working channel of a flexible endoscope, the lumen of a catheter or to
function as a catheter itself.
Furthermore the elastic member may be coated with a suitable material, such
as a polymer.
The elastic member has a distal end portion with a specific curved shape
when not subject to mechanical stress. In a first embodiment, the elastic
member is of sufficient strength and rigidity to enable a surgeon to grasp
and manipulate a body structure, such as a bone, thereby. In the first
embodiment, the elastic member includes a distal end structure which may
be a pointed tip or a structure which serves to protect the patient's body
and to prevent complete withdrawal of the elastic member into the cannula.
As the elastic member is distally extended from the cannula, it curves
around the body structure sufficiently for grasping and manipulating the
body structure.
In a second embodiment, the elastic member may be of less substantial
construction, and its distal end portion is adapted to retain a ligature.
In order to pass the ligature around a blood vessel or bone, the surgeon
need only place the distal end of the apparatus near the vessel or bone,
and extend the elastic member from the cannula, without any required
lateral angular motion of the cannula. The elastic member returns to its
specific curved shape as it extends beyond the catheter, wrapping itself
around the blood vessel or bone. The ligature may then be attached to the
distal end of the elastic member, and the elastic member may be withdrawn
into the cannula, to pull the ligature around the vessel or bone. By
pre-attaching the ligature to the elastic member, the ligature may be
passed around the vessel or bone upon extension rather than retraction of
the elastic member. The apparatus may further include a means for
automatically attaching the ligature to or unattaching the ligature from
the elastic member.
The elastic member, if made of pseudoelastic material, will not readily
break during repeated use, since metal fatigue does not occur under
pseudoelastic use conditions. The instrument operates even though the
cannula is not swept over any degree of motion. The instrument is of a
simple design, and is of relatively low production cost.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1--1 to 1-3 illustrate a first embodiment of the present invention.
FIG. 1-1A is a cross-sectional diagram, showing the elastic member disposed
within the cannula, in a mode in which the elastic member has a distal end
structure.
FIG. 1-1B is a cross-sectional diagram, showing a mode in which the elastic
member has a pointed distal tip,
FIGS. 1-2A and 1-2B illustrates modes of the elastic member, returning
toward a curved shape and a corkscrew shape upon extrusion from the
cannula, respectively.
FIGS. 1-3A, 1-3B and 1-3C illustrate linear, lateral, and axial
manipulation of a bone.
FIGS. 1-4 to 1-12 illustrate a second embodiment of the present invention.
FIG. 1-4 is a cross-sectional diagram, showing the elastic member fully
disposed within the cannula.
FIGS. 1-5A and 1-5B show alternative modes of the ligature retainer.
FIG. 1-6 shows extension of the elastic member of FIG. 1-5A around a blood
vessel.
FIGS. 1-7A, 1-7B, 1-7C, 1-7D, 1-7E and 1-7F illustrate a means for
automatically grasping a ligature which is passed around a blood vessel.
FIGS. 1-8A, 1-8B, 1-8C and 1-8D illustrate an alternative mode of
automatically grasping the ligature.
FIG. 1-9 illustrates another alternative mode of automatically grasping the
ligature.
FIGS. 1-10A, 1-10B, 1-10C and 1-10D illustrate how the apparatus may be
used to pass the ligature and automatically tie a half-hitch knot therein.
FIG. 1-11 shows a sliding sleeve which aids in tying the half-hitch knot.
FIGS. 1-12A, 1-12B, 1-12C illustrate how the apparatus may be used to pass
the ligature and automatically tie a logger's knot therein.
FIG. 1-13 shows a prior art apparatus, and illustrates the wide angle of
access needed therefor.
FIGS. 2-1 to 2-6 illustrate the first embodiment of the present invention,
which longitudinally extrudes an elastic needle through the distal end of
a cannula.
FIG. 2-1A is a cross-sectional view, showing the elastic needle held inside
the cannula in a straightened configuration under mechanical stress.
FIG. 2-1B shows partial extrusion of the elastic needle from the cannula,
with the extruded portion of the needle returning toward its curved
configuration by elastic shape memory.
FIG. 2-1C shows the needle fully extruded from the cannula, and released
from the cannula insert.
FIGS. 2-2A, 2-2B, 2-2C, 2-2D and 2-2E show alternative modes of the distal
end portion of the cannula insert.
FIG. 2-3 is a view of the distal end portion of the cannula insert, showing
a raised release signal tab formed therein.
FIG. 2-4A illustrates an integrally constructed mode of the distal end
portion of the first embodiment, showing the enlarged transverse dimension
of the end portion of the cannula insert.
FIG. 2-4B shows an alternative, non-integral mode of the distal end portion
of the cannula insert, formed of a compressible material.
FIG. 2-5 is a view of the distal end portion of the cannula insert, showing
an indented distal face therein.
FIG. 2-6 is a cross-sectional view of the proximal end portion of the first
embodiment, showing a suture retention bobbin within the cannula insert.
FIGS. 2-7 to 2-10 illustrate a second embodiment to the present invention,
which extrudes the elastic needle laterally rather than longitudinally.
FIGS. 2-7A is a cross-sectional view showing a cannla, shaft, and plunger
of the second embodiment.
FIG. 2-7B is a cross-sectional view of an alternative mode of the proximal
end portion of the second embodiment.
FIG. 2-7C is a cross-sectional view of another alternative mode of the
proximal end portion of the second embodiment.
FIG. 2-7D is an enlarged cutaway view of the proximal end portion of the
alternative mode shown in FIG. 2-7B.
FIG. 2-7E is a perspective view of the proximal end cap of the alternative
mode shown in FIG. 27C.
FIG. 2-8 is a cross-sectional view of the distal end portion of the second
embodiment, showing a suture retention bobbin therein.
FIG. 2-9 is a cross-sectional view of the second embodiment, taken at line
9--9 of FIG. 2-7A, showing grooves in the shaft and cannula, and groove
engaging tabs in the plunger, for causing rotation of the shaft.
FIG. 2-10 is a cutaway perspective view of the distal end portion of the
second embodiment, showing the unwinding of the curved needle through the
aperture.
FIG. 2-11A illustrates the present invention being used to deliver the
needle to a deep wound for suturing.
FIG. 2-11B illustrates the present invention being used in arthroscopic
surgery on a knee.
FIGS. 2-12 to 2-15 illustrate a third embodiment of the present invention,
which is used to insert ring clips into tissue to hold a wound closed.
FIG. 2-12A is a cutaway view of the third embodiment, illustrating a ring
clip held therein.
FIG. 2-2B illustrates extrusion of the ring clip.
FIG. 2-12C illustrates an alternative mode of the third embodiment, adapted
for use with an extended ring clip which is held therein.
FIGS. 2-13A and 2-13B, and 2-13C and 2-13D, illustrate a marker which
indicates a first and a second direction of extrusion of the ring clip,
respectively.
FIG. 2-14 is a cross-sectional view of another alternative mode of the
third embodiment, adapted for serial extrusion of a plurality of ring
clips held therein.
FIG. 2-15A illustrates yet another mode of the third embodiment, with the
plurality of ring clips held in a magazine.
FIG. 2-15B illustrates an internal piston return spring.
FIG. 2-16A illustrates manipulation of the extended distal segment of the
ring clip of FIG. 2-12C.
FIG. 2-16B illustrates the severing of the extended distal segment of FIG.
2-16A.
FIGS. 2-17A, 2-17B and 2-17C illustrate various modes of a ring clip.
FIG. 3-1 is a view of an unexpanded barrier device (not shown) within a
housing. FIG. 3-2 through FIG. 3-5 are progressive cross-sectional views
through line a--a of FIG. 3-1: showing the use of the device of FIG. 3-1.
The figures show, respectively, FIG. 3-2, constrained; FIG. 3--3, expanded
(memory); FIG. 3-4, pouched; and FIG. 3-5, withdrawal configurations.
FIG. 3-6A, B, C and D show alternate embodiments of the device of FIG. 3-1
through line b--b.
FIG. 3-7 and FIG. 3-8 show alternate embodiments of the barrier member in
the expanded (memory) configuration.
FIG. 3-9A shows cross-sectional embodiments through line b--b of FIG. 37.
FIGS. 3-10, 3-11 and 3-12 detail alternate expanded loop configurations.
FIG. 3-13 is a schematic representation of another embodiment of a device
for deploying an internal drape, and
FIGS. 3-14 and 3-15 are schematic representations of yet another embodiment
of device for deploying an internal bag, showing the device before and
after withdrawal of the drape into the shalt of the instrument.
FIGS. 3-16, 3-17 and 3-18 illustrate the use of a bushing which can be used
with any of embodiments 3-1 to 3-15.
FIGS. 3-19, 3-20, 3-21 and 3-22 illustrate a necked-loop configuration
which can be incorporated in any of the embodiments, illustrated in FIGS.
3-1 to 3-18.
FIG. 4-1A is a side view of an unexpanded screen device within a duct,
placed downstream from a blocking calculus. FIG. 4-1B shows the screen
device, the deployment end of which has been placed upstream from the
blocking calculus. FIG. 4-1C shows a screen device which has been expanded
upstream from a blocking calculus. FIG. 4-1D shows a screen device in
place after calculus fragmentation.
FIG. 4-2A, B, C and D shows various stages of deployment of a tasseled
surgical screen.
FIG. 4-3, 4--4 and FIG. 4-5 show alternate embodiments of the surgical
screen portion of a device of this invention.
FIG. 5-1 is a cross-sectional view of a constrained retractor device, FIGS.
5-2, 5-3, 5-4 and 5--5 5-6 show alternate top views of expanded
(unconstrained) retractor devices. FIGS. 5-7, 5-8, 5-9, 5-10 and through
5-11 show alternate side views of expanded retractor devices. FIGS. 5-12
and 5-13 show alternate end views of expanded retractor devices. FIGS.
5-14 and 5-15 show alternate cross sectional views of constrained
retractor devices, the cross section taken along line a--a of FIG. 5-1.
FIG. 6-1 is an external view of a device of this invention.
FIGS. 6-2 and 6-3 are alternate cross-sectional views of a sheath of this
invention, the cross sections being taken vertically along the
longitudinal axis of FIG. 6-1.
FIG. 6-4 is an alternate cross-sectional view of a sheath of this
invention, the cross section being taken vertically along the longitudinal
axis.
FIG. 6-5 is a cross-sectional view of the device of FIG. 6-1 taken across
the longitudinal axis, along line b--b of FIG. 6-1. FIG. 6--6 is a
cross-sectional view of the device of FIG. 6-1 taken across the
longitudinal axis, along line c--c of FIG. 6-1.
FIG. 6-7 is a cross-sectional view of a cutting edge of a cutting blade of
this invention.
FIGS. 6-8, 6-9, 6-10 6-11 and FIG. 6-12 are alternate side views of the
device of FIG. 6-1 when the cutting blade is deployed.
FIG. 6-13, 6-14, 6-15, 6-16, 6-17, 6-18, 6-19 and FIG. 6-20 are alternate
top views of typical elastic blades of this invention.
FIG. 7-1 shows an instrument of this invention.
FIGS. 7-2A, B, C and D show the deployment end of a bladed instrument of
this invention.
FIGS. 7-3A, B and C and 7-4A, B and C are longitudinal cross-sectional
views of alternate elastically deployable stems, in longitudinally
constrained and longitudinally unconstrained configurations.
FIGS. 7-5A and B, 7-6A and B and 7-7A, B and C each show alternate views of
an elastically deformable stem of this invention.
FIGS. 7-8A, B, C, D, E and F and 7-9A, B, C, D, E, F, G, H and I show
alternate elastic members suitable for use in an elastically deformable
stem of this invention.
FIGS. 7-10A and B show alternate views of a device of this invention having
two pivoted blades, each blade having a longitudinal slot proximal the
pivot.
FIGS. 7-11A, B and C show alternate views of a device of this invention
having two blades, two bars, and four pivots.
FIGS. 7-12A, B, C, D, E, and F show alternate cross-sections of the device
of FIG. 7-1, taken through line 12--12.
FIGS. 7-13A, B, C, D, E and F show various blades suitable for use herein.
FIGS. 7-14A, B, C, D and E show various blade cross-sections, taken through
line 14--14 of FIG. 7-13.
FIG. 8-1 is an isometric view of a device of the invention;
FIGS. 8-2A, 8-2B and 8-2C are cross-sections through the device shown in
FIG. 8-1, taken at lines A--A, B--B and C--C respectively;
FIGS. 8-3A, 8-3B, 8-3C, 8-3D and 8-3E are elevational views of a first
embodiment of the device shown in FIG. 8-1 at various stages during a
cutting operation;
FIGS. 8-4A, 8-4B and 8-8C are elevational views, partially in section, of
another embodiment of the device at various stages during a cutting or
grasping operation.
FIGS. 8-5A, 8-5B, 8-5C, 8-5D and 8-5E illustrate an embodiment of a device
in accordance with this invention in which the end portions and body
portions of the elongate elements are integral and are moved by a
rotational actuator made of a material other than a pseudoelastic
material.
FIGS. 8-6A, 8-6B, 8-6C, 8-6D and 8-6E illustrate representative cross
sections of end portions of the elements adapted to grasp or cut an
object.
FIGS. 8-7A, 8-7B; 8-7C, 8-7D and 3-7E illustrate various actuating means
which function to cause the elements to splay apart and come together and,
optionally, rotate the elements, and/or withdraw the elements into or out
of the hollow component.
FIG. 8--8 illustrates an embodiment of the device of this invention in
which the end portions are curved when at least partially unconstrained
and pinned together pivotally at their tips.
FIG. 8-9 demonstrates a method of using a grasping device of this
invention.
FIGS. 8-10A, 8-10B and 8-10C illustrate an embodiment of the device of this
invention in which the elements are splayed and in which the body portions
of the elements are bent when the elements are unconstrained.
FIGS. 8-11A and 8-11B illustrate a device of this invention in which the
elements have end portions beyond a pivot point, and in which the body
portions of the elements are of pseudoelastic material and when
unconstrained are bent to splay the end portions and position them at a
desired angle with respect to the hollow component. The body portions act
as actuating means to open and close the end portions of the elements to
dissect, grasp and/or cut an object.
FIG. 8-12 illustrates a device similar to the device in FIG. 8-11B, but in
which the body portions of the elements are made of a pseudoelastic
material and have a bend of about 90.degree..
FIG. 8-13 illustrates another device in accordance with this invention.
FIG. 1-13 shows the use of a prior art apparatus 700 for passing a ligature
(not shown) around a particular blood vessel 703 which is situated among
other blood vessels 704. In order to place the operative distal end 710
into a position 715 from which the end 710 is directly accessible, it is
necessary to swing the entire apparatus 700 through a very wide angle of
motion 720. This wide angle requires a very large entry wound 740 through
the patient's tissues 730. It will be understood that such a wide angle of
motion is impossible to achieve if the apparatus 700 is being used through
an arthroscopic or other small endoscopic surgical entry wound 735 through
the patient's tissues 730.
As will be understood from the following description and from the
accompanying drawings, the present invention is an apparatus usable
through such a small entry wound.
In a first embodiment 100, shown in FIGS. 1--1 to 1-3, the present
invention includes a cannula 10 and a member 12. Although the present
invention may be practiced with a member 12 which is fashioned of another
appropriate material, such as spring steel, the preferred material is a
pseudoelastic material, preferably a shape memory alloy and in particular
a shape memory alloy that exhibits superelasticity. The member 12 will
hereinafter be referred to as a elastic member 12, and its distal segment
14 will be referred to as a elastic distal segment 14. In a preferred
embodiment the member is made of a superelastic shape memory alloy and the
elastic distal segment 14 has a first shape when the alloy of the elastic
distal segment 14 is in a substantially austenitic phase and the distal
segment 14 is extended distally from the cannula 10 and is not subject to
mechanical stress. The elastic distal segment 14 may be mechanically
stressed into a second shape (i.e., when the distal segment 14 is held
within the cannula 10), wherein at least a portion of the alloy has
changed to a stress-induced-martensite phase.
FIGS. 1-1A-B show the elastic distal segment 14 elastically deformed into a
second, straight shape within the cannula 10. FIG. 1-2A shows one mode of
the first shape, with the elastic distal segment 14 returning toward an
arced first shape upon extrusion from the cannula 10. FIG. 1-2B shows an
alternative mode of the first shape, wherein the elastic distal segment 14
returns toward a corkscrew first shape upon extrusion from the cannula.
As shown in FIG. 1-1A, the elastic member 12 also includes a proximal
segment 16 which is relatively straight, to allow its easy insertion into
the proximal end of the cannula 10.
The distal and proximal segments may, suitably, be integrally formed of a
unitary wire or rod, or the proximal segment may be formed of a different
material and coupled end-to-end with a elastic distal segment. If the
segments 14 and 16 are formed of a unitary construction, the proximal
segment 16 does not, preferably, have a curved shape when it is in an
unstressed condition, unlike the elastic distal segment 14. Although the
member 12 is referred to herein as a elastic member 12, it will be
understood that, as explained, only the distal end segment 14 need be
elastic. It will be further understood that the distal end segment 14 as
well as the proximal segment 16 may be formed of any suitable material,
which may or may not be the same.
The elastic member 12 may also include a distal end structure 18, as shown
in FIG. 1-1A. The distal end structure 18 is a contact or grip means which
improves the grip of the apparatus 100 upon an object. The distal end
structure 18 also prevents the complete withdrawal of the elastic member
12 through the cannula 10, to preserve the apparatus 100 as an integral
unit. The smooth surface and shape of the distal end structure 18 serve as
a safety means which helps to reduce tissue damage upon insertion of the
apparatus 100 into a wound, or through tissue, or through an arthroscopic
or other such endoscopic surgical entry wound. In the illustrated
embodiment, the distal end structure 18 is substantially semi-spherical,
with a diameter roughly equal to that of the cannula 10. This protects the
patient's tissues from the blunt distal end of the cannula 10, while also
preventing complete withdrawal of the elastic member 12 from the cannula
10. The distal end structure 18 may be either unitarily constructed with
the elastic distal segment 14, or may be formed of a different material
and coupled thereto in any conventional manner. It is to be understood
that the distal end structure 18 can have any blunted shape, and may even
be spherical or bullet shaped.
As shown in FIG. 1-1B, the elastic member may have a pointed distal end
structure 19, which, like the distal end structure 18 of FIG. 1-1A,
improves the mechanical gripping of the apparatus upon a bone or other
object. It may be preferred that distal end structure 19 be integral with
the elastic member.
The apparatus 100 may, suitably, be further adapted with a handle structure
for extending the elastic member 12 through the cannula. In one mode, the
handle structure may include a thumb ring 20 coupled to the proximal end
of the elastic member 12, and one or more finger rings 22 coupled near the
proximal end of the cannula 10. The surgeon inserts the elastic member 12
through the cannula 10 by pressing on the thumb ring 20 while holding the
finger rings 22 stationary, and withdraws the elastic member 12 into the
cannula by pulling the thumb ring 20 in the opposite direction. Of course,
other handle devices are within the scope of all of the embodiments of
this invention, such as a pistol grip, or a scissor-action apparatus, or
the like. Withdrawal of the elastic member 12 may be assisted by a spring
(not shown).
As shown in FIG. 1-2A, when the elastic member 12 is inserted through the
cannula 10 with motion 24, the elastic distal segment 14 emerges from the
distal end of the cannula 10. In a preferred embodiment in which
superelastic shape memory alloy is utilized, the elastic distal segment 14
has its stress-induced-martensite condition at least partially relieved of
stress by the absence of any restraining cannula. The alloy of the elastic
distal segment 14 undergoes at least a partial reversion toward the
austenitic phase, and the elastic distal segment 14 returns toward its
first shape with motion 26.
It will be understood that the curvature of the elastic distal segment 14
need not necessarily be circular, nor coplanar with the axis of the
cannula 10, within the scope of this invention. For example, the distal
segment 14 might be formed to curve radially about the axis of the cannula
upon extrusion therefrom, in a corkscrew fashion, as shown in FIG. 1-2B.
As will be understood, the elastic distal segment 14 may be formed to have
any desired shape or arc or radius of curvature, to suit the apparatus for
a given purpose.
As shown in FIGS. 1-3A-C, the apparatus 100 may be used to manipulate a
bone 3 or other structure in a patient, or any other suitable object. The
specific body members which are discussed herein are listed solely to aid
in the understanding of the invention, and do not affect the scope of the
invention.
It will be understood that the first embodiment 100 may be constructed in a
variety of sizes and with an elastic member of a variety of lateral
dimensions, cross-sectional configurations, and strengths, for suitable
use in manipulating a wide variety of body members or other objects, For
example, a very small apparatus with a very thin elastic member may be
desirable in manipulating small or delicate body members such as
individual nerves or terminal arteries. On the other hand, a large
apparatus with a thick elastic member having great strength may be
required in order to manipulate a larger body member such as a broken
femur, or a bulky organ, or a prosthesis or other mechanical object. Also
the apparatus may be long and/or flexible, so that it can be used in the
channel of an endoscope (rigid or flexible), in the lumen of a catheter,
or as a catheter itself.
The elastic distal segment 14 of the elastic member 12 may be inserted into
or wrapped around the body structure 3, and the apparatus 100 may be
moved, to manipulate the structure 3. Extension of the elastic member 12
into grasping connection with the body member 3 does not require any
lateral movement of the apparatus 100, but only requires linear insertion
of the elastic member 12 through the cannula 10. This permits the
apparatus 100 to be used in closely confined surgical sites, or through a
very small surgical opening such as may typically be used to gain
arthroscopic access to a knee joint, for example.
By forming the elastic distal segment 14 to have a non-stressed shape which
curves in a particular direction, the apparatus 100 may be constructed for
suitable hooking of a body member which has a given orientation. With the
curvature shown in FIG. 1-3A, the apparatus 100 may be suited for linear
pulling or pushing of the body structure 3 in the direction 28 shown. With
the curvature shown in FIG. 1-3B, the apparatus 100 may be suited for
lateral manipulation of the body structure 3 in the direction 30, as
shown. As shown in FIG. 1-3C, if the elastic distal segment 14 curves in a
corkscrew shape, the apparatus 100 may be readily used to push or pull the
body structure 3 along the axis of the body structure 3, in direction 32
as shown.
The apparatus 100 may be adapted with a marker 31, as shown in FIG. 1-3A,
for indicating the direction and orientation in which the particular
elastic member 12 will curve upon extrusion. The marker 31 may be, for
example, printed upon the cannula 10, or may be a raised or indented
portion thereof. As it is desirable that the marker 31 not cause any
trauma to an entry wound, a printed marker may be the preferred mode. It
will be understood that the marker may be placed at any desired point
along the length of the cannula. For example, a marker placed immediately
adjacent to the distal tip of the apparatus will likely be visible to an
arthroscopic surgeon through his or her arthroscopic viewing apparatus. On
the other hand, or in addition, a marker placed near the proximal end of
the apparatus will remain in plain sight during surgery, as it will remain
outside the patient's body. The apparatus 100 may include any suitable
means for ensuring that the elastic member 12 curve in the indicated
direction. For example, the distal segment 16 may be formed of a square
cross-section, with the proximal end opening (not shown) of the cannula 10
being formed of a similar shape, such that the elastic member 12 cannot
rotate within the cannula 10. Alternatively, the cannula 10 may have a peg
(not shown) which engages a longitudinal slot (not shown) in the elastic
member 12, or the elastic member 12 may have a peg (not shown) to engage a
longitudinal slot (not shown) in cannula 10.
FIGS. 1-4 to 1-12 illustrate a second embodiment 200 of the present
invention. In this embodiment, the elastic member 12 need not include a
distal end structure, and may be fully withdrawn into the cannula 10.
Although the second embodiment 200 is hereinafter described as being used
for passing a ligature around a blood vessel, it will be understood that
the ligature may be passed around any other body structure or other
object, within the scope of this invention. If the non-deformed shape of
the distal segment of the elastic member is substantially circular, this
has the important advantage that, during extension and withdrawal of the
elastic distal segment, that portion of the elastic distal segment which
is already extruded from the cannula and adjacent the blood vessel will
not apply any lateral or radial forces upon the blood vessel. It will,
therefore, be understood that it is advantageous to form differing modes
of the second embodiment, wherein each has an elastic member whose distal
segment is of a given radius of curvature in its non-deformed first shape.
This allows the surgeon to select an appropriately sized apparatus for
passing a ligature around any size of blood vessel, and is within the
scope of this invention. It will be understood that the same principle
applies equally to the first embodiment described above with regard to
FIGS. 1--1 to 1-3. Also the apparatus may be long and/or flexible, so that
it can be used in the channel of an endoscope (rigid or flexible), in the
lumen of a catheter, or as a catheter itself.
The elastic distal segment 14 of FIG. 1-6 is adapted with a ligature
retainer means 34 which releasably retains the ligature 36. FIGS. 1-5A-B
show the ligature retainer 34 as a hook and a hole, respectively. In
either mode, the ligature retainer 34 may either be cut into the wire of
the elastic distal segment 14, or may be bent thereinto by plastically
deforming the wire of the elastic distal segment 14. Other suitable means
may be employed without departing from the scope of this invention. It
will be understood that the ligature retainer 34 may be fashioned in any
desired orientation relative to the plane of curvature of the elastic
distal segment 14. If the hook mode of the ligature retainer 34 is used,
in order to prevent the hook 34 from catching on the inner lip 33 of the
distal opening of the cannula 10 upon withdrawal, the lip 33 may be
rounded off, as shown in FIG. 1-5A.
The second embodiment 200, like the first, may be adapted with at least one
marker 31 for indicating a predetermined direction of curvature of the
elastic member, and with suitable handles 20 and 22 or other means for
extending and retracting the elastic member. A spring may be used to
assist retraction of the elastic member 12.
As shown in FIG. 1-6, upon extrusion from the cannula 10, the elastic
distal segment 14 curves around the vessel 5 with motion 38. It will be
understood that the elastic distal segment 14 need not actually touch the
vessel 5, but is shown in such contact for convenience. With the elastic
member 12 wrapped around the blood vessel 5, the ligature (not shown) may
be inserted into the ligature retainer 34 using tweezers, forceps, or the
like. Withdrawal of the elastic distal segment 14 into the cannula 10
draws the ligature around the blood vessel 5 with motion 40. As will be
understood, the ligature may also be inserted into the ligature retainer
34 before the elastic distal segment 14 is passed around the blood vessel
2, in which instance the ligature is passed around the blood vessel 5 upon
extension of the elastic member 12 around the blood vessel 5 with motion
38, if the ligature retainer 34 is appropriately formed.
The apparatus 200 may further be adapted with means for automating the
ligature's attachment to, or unattachment from the elastic member. FIGS.
1-7A-F illustrate one mode of this means. One end 35 of the ligature 36 is
coupled to the cannula 10, for example by being tied or otherwise coupled
to a post 44. Upon extension from the cannula 10, the elastic distal
segment 14 curves with motion 38 around the vessel 5, as shown in FIG.
1-7B. The elastic distal segment 14 is constructed such that its return
toward the unconstrained first shape brings the ligature retainer 34 into
grasping contact with the held portion 35 of the ligature 36, as shown in
FIG. 1-7C.
Upon retraction, the elastic member 12 draws the ligature 36 around the
vessel 5 with motion 40 (the reverse of motion 38), and the ligature 36
slides through the ligature retainer 34, as shown in FIG. 1-7D. Upon full
retraction, shown in FIG. 1-7E, the ligature 36 will be doubled around the
vessel 5. If it is desired that only a single loop of ligature 36 pass
around the vessel 5, this may be accomplished by simply releasing the
trailing end 37 of the ligature 36, and withdrawing the apparatus 200
until the trailing end 37 passes around the vessel 5, as shown in FIG.
1-7F. Alternatively, a doubled suture (not shown) can be placed over the
post and held by the post such that only one strand of the suture is
hooked by ligature retainer 34.
The post 44 in the embodiments shown in FIGS. 1-7, 1-9, 1-10, 1-11, and
1-12, and the loop grabber 42 shown in FIGS. 1-8 and 1-9, are shown to be
rigidly attached to the cannula 10. However, beth post 44 and loop grabber
42 could consist of a tongue (not shown) or a cam (not shown) to which
sutures may be attached. Such a tongue or cam would preferably be biased
flush with the wall of the cannula 10 initially, but would be mechanically
forced to extend in a direction sideways from the cannula when the elastic
member 12 is extended from the end of the cannula. In this fashion, a
suture would be held against the wall of cannula 10 until the elastic
member is extended, at which time the post and/or loop grabber would
extend sideways from the wall of the cannula 10 such that the post 44 will
hold the suture in a better location for the ligature retainer 34, and/or
such that the suture can be attached to the loop grabber 42. Upon
withdrawal of elastic member 12 the tongue or cam will preferably return
to their flush position. It is to be understood that the configuration of
a post or a loop grabber can be a tongue, cam or other suitable structure.
In an alternative mode, the second embodiment 200 may be fashioned such
that the ligature is passed around the vessel or bone upon extension,
rather than retraction, of the elastic member. FIGS. 1-8A-D illustrate one
such mode of the apparatus 200. A loop 39 is formed in the ligature 36,
and the loop 39 is held in the ligature retainer 34, preferably facing in
the direction in which the elastic distal segment 14 will curve upon
extension from the cannula 10.
The cannula 10 includes a proximal facing loop grabber 42, which may be a
hook. Upon extension, the elastic distal segment 14 curves around the
vessel 5 and places the loop 39 of ligature 36 over the loop grabber 42.
Upon retraction of the elastic member 12, the loop grabber 42 prevents the
ligature retainer 34 from drawing the loop 39 back around the vessel 5. If
the ligature retainer 34 is a groove or hook, the loop 39 is simply
withdrawn therefrom upon retraction of the elastic member 12. If the
ligature retainer 34 is a hole or eye, the ligature 36 slips therethrough
upon retraction of the elastic member 12. Forceps can be used, instead of
relying on the loop grabber 42, to grasp the ligature 36, if desired. In
an alternative embodiment, the ligature 36 may be placed into the ligature
retainer 34 as a simple raised strand, to be passed around the vessel and
grasped with forceps.
FIG. 1-9 illustrates an equivalent mode of the apparatus 200 which passes
the ligature 36 during extension of the elastic member 12. The loop
grabber 42 may be elevated such that it has a segment 43 which extends
beth proximalward and cannulaward. The ligature retainer 34 may be formed
as an eye, through which the ligature 36 is positioned. The cannula 10
may, suitably, be adapted with a post 44 to which the ligature 36 may be
anchored. It will be understood that, by forming the elastic distal
segment 14 to have a curvature upon extension such that the eye 34 is
brought into contact with the segment 43 of the loop grabber 42, and by
extending the elastic member 12 until the eye 34 extends slightly past the
segment 43, the ligature 36 will be forced over the segment 43 as shown.
This and other alternative modes of the ligature catching means are within
the scope of this invention. Alternatively, a doubled suture (not shown)
can be placed over the post and held by the post such that only one strand
of the suture is hooked by ligature retainer 34.
In any of the modes, the ligature retainer may include two grooves or eyes
on opposite ends of a Y-shaped distal end of the elastic member. In such a
mode, a segment of the ligature may be held between the arms of the Y for
presentation to the cannula's hook. This may be advantageous if the loop
of the ligature is too limp to be easily caught by the cannula's hook. If
formed as a hole, the ligature retainer may include a narrowed, slot-like
portion at its proximal end, into which the ligature may be wedged. The
narrowed portion will provide a tight grip on the loop of ligature during
extension about the vessel, while the larger portion of the hole will
enable the ligature to easily slip therethrough during retraction of the
elastic member. These, and various other modifications may be made to the
ligature retainer, within the scope of this invention.
As shown in FIGS. 1-10A-D, the second embodiment 200 may be used to create
a knot in the ligature 36. A loop 39 of the ligature 36 is placed around
the cannula 10 in the following manner, as explained with reference to
FIG. 1-10A. An end 35 of the ligature 36 is held at some point toward the
proximal end (not shown) of the cannula 10. The ligature 36 is passed by a
first side (the far side in FIG. 1-10A) of a post 44, then over the
cannula 10 toward a second side (the near side in FIG. 1-10A) of the
cannula 10 at a point distalward from the post 44. From there, the
ligature 36 is passed around the cannula 10 back to the first side, then
around the post 44 proximal to loop 39 on the second side. The trailing
end 37 of the ligature 36 is then drawn toward the proximal end (not
shown) of the apparatus 200 to draw the ligature 36 at least somewhat
tight around the cannula 10 and post 44. The post 44 may include a
protrusion 46 to keep the trailing end portion 37 of the ligature 36
elevated above the cannula 10, for ease of grasping the ligature 36. The
cannula 10 may include an indented or grooved segment 48, to keep the loop
39 of ligature 36 in a given position about the cannula 10.
As seen in FIG. 1-10B, with the apparatus 200 in position at the vessel 5,
the elastic member 12 may be extended until the ligature retainer 34
engages the trailing end portion 37 of the ligature 36. Then, the trailing
end portion 37 alone may be drawn around the vessel 5 as shown in FIG.
1-10C. Finally, by sliding the loop 39 distally off of the cannula 10,
with motion 50, until the loop 39 passes completely over and around the
ligature retainer 34, the trailing end 37 may be drawn through the loop
39, to form a half-hitch knot as shown in FIG. 1-10D. The knot may then be
tightened, as needed.
FIG. 1-11 illustrates the addition of a sliding sleeve 52, which slides in
and out of the cannula 10. The sleeve 52 is disposed within the cannula
10, and the elastic member 12 is, in turn, disposed within the sleeve 52.
Extension and retraction of the elastic member 12 may permit the sleeve 52
to slide a short, restricted distance. The loop 39 of the ligature 36 may
be placed over the sliding sleeve 52 rather than over the cannula 10
itself. Then, after the trailing end 37 has been pulled around the vessel
as described above, the sleeve 52 may be slid into the cannula 10, to
dislodge the loop 39. In the final stages of retracting the elastic member
12 back into the sliding sleeve 52, the elastic member 12 may engage the
sliding sleeve 52 such that the sliding sleeve 52 is automatically
withdrawn into the cannula 10 and automatically releases the loop 39, if
the tolerance between cannula 10 and sliding sleeve 52 is small and the
loop 39 cannot readily pass between sliding sleeve 52 and cannula 10. If
the ligature retainer 34 is kept within the sleeve 52 during the sliding,
the loop 39 will not catch on the ligature retainer 34. The sliding sleeve
52 may be biased toward its extended position by a spring (not shown).
Alternatively, in FIGS. 1-10 and 1-11, end 35 of ligature 36 may be
fastened to post 44.
FIGS. 1-12A-C illustrate how the apparatus 200, with or without the sliding
sleeve, may be used to form a logger's knot around a vessel 5. The
ligature 36 is loaded onto the apparatus 200 by simply passing a loop 39
of the ligature 36 over the distal end of the cannula 10, and by placing
both ends 37 and 35 of the ligature 36 over the protrusion 46 on the post
44. The elastic member is extended and retracted, to catch and retrieve
both ends 35 and 37 of the ligature 36, as described above. Then, both
ends 37 and 35 of the ligature 36 are passed around the vessel 5 and are
drawn through the loop 39. Other knots may be tied using the apparatus
200, within the scope of this invention. In all of the embodiments
described herein, any suitable form of activating means may be utilized,
for example, syringe-plunger mechanisms, slider mechanisms, scissor action
mechanisms, pistol grip mechanisms or the like.
Various other modifications may be made to the apparatus, including those
suggested by the following description of a "Suturing Instrument".
Another form of the present invention discloses an apparatus and method
which, through the properties of elastic materials, preferably
pseudoelastic materials, such as pseudoelastic shape memory alloys,
overcome the prior art's disadvantages listed above. The apparatus is a
delivery system for delivering, into a deep wound or into an arthroscopic,
endoscopic, laparoscopic, or other such surgery site, a needle which is
constructed of an elastic material, preferably a shape memory alloy.
Although pseudoelasticity is exhibited in both linear and non-linear
variations, the present invention deals preferably with superelasticity,
and further references to materials having this property will simply be
designated as being "pseudoelastic" or having shape memory. It will be
understood, however, that the present invention may employ any appropriate
elastic material, preferably shape memory alloy, whether linearly or
non-linearly pseudoelastic. The term "needle" as used herein includes
solid and hollow needles.
In a first embodiment, the present invention discloses a deep needle
delivery apparatus, including a longitudinally extending cannula which may
be inserted through an arthroscopic or other such incision or into a deep
wound or into a natural body orifice. Inside the cannula, the apparatus
has a cannula insert member, whose distal end includes a means for
grasping a needle. The needle is held entirely within the cannula, in a
straightened configuration.
Holding the needle within the cannula in a straightened configuration
offers two advantages in reducing trauma to the patient's tissues: because
no portion of the needle extends from the cannula during insertion of the
cannula into the patient's body, the apparatus will not snag the tissues
upon insertion, and because the apparatus has a minimized transverse
dimension, only a small entry incision or site is required. The minimized
transverse dimension may also permit the cannula to be used in a channel
of an endoscope (rigid or flexible), in the lumen of a catheter, or as a
catheter itself.
The apparatus includes a minimum of moving parts and is, therefore, both
less subject to failure and less expensive than prior needle delivery
apparatuses. The apparatus' simplicity of design results in a unique
simplicity of use, as well.
In a second embodiment, the needle is extruded laterally rather than
longitudinally, which may permit insertion of the needle into otherwise
inaccessible portions of a patient's tissues.
In a third embodiment, the apparatus inserts ring dips (solid or hollow)
rather than a needle.
FIGS. 2-1 to 2-6 illustrate the first embodiment of the present invention,
which longitudinally extrudes an elastic needle through the distal end of
a cannula.
FIG. 2-1A is a cross-sectional view, showing the elastic needle held inside
the cannula in a straightened configuration under mechanical stress.
FIG. 2-1B shows partial extrusion of the elastic needle from the cannula,
with the extruded portion of the needle returning toward its curved
configuration by elastic shape memory.
FIG. 2-1C shows the needle fully extruded from the cannula, and released
from the cannula insert.
FIGS. 2-2A-E show alternative modes of the distal end portion of the
cannula insert.
FIG. 2-3 is a view of the distal end .portion of the cannula insert,
showing a raised release signal tab formed therein.
FIG. 2-4A illustrates an integrally constructed mode of the distal end
portion of the first embodiment, showing the enlarged transverse dimension
of the end portion of the cannula insert.
FIG. 2-4B shows an alternative, non-integral mode of the distal end portion
of the cannula insert, formed of a compressible material.
FIG. 2-5 is a view of the distal end portion of the cannula insert, showing
an indented distal face therein.
FIG. 2-6 is a cross-sectional view of the proximal end portion of the first
embodiment, showing a suture retention bobbin within the cannula insert.
FIGS. 2-7 to 2-10 illustrate a second embodiment of the present invention,
which extrudes the elastic needle laterally rather than longitudinally.
FIG. 2-7A is a cross-sectional view showing a cannula, shaft, and plunger
of the second embodiment.
FIG. 2-7B is a cross-sectional view of an alternative mode of the proximal
end portion of the second embodiment.
FIG. 2-7C is a cross-sectional view of another alternative mode of the
proximal end portion of the second embodiment.
FIG. 2-7D is an enlarged cutaway view of the proximal end portion of the
alternative mode shown in FIG. 2-7B.
FIG. 2-7E is a perspective view of the proximal end cap of the alternative
mode shown in FIG. 27C.
FIG. 2-8 is a cross-sectional view of the distal end portion of the second
embodiment, showing a suture retention bobbin therein.
FIG. 2-9 is a cross-sectional view of the second embodiment, taken at line
9--9 of FIG. 2-7A, showing grooves in the shaft and cannula, and groove
engaging tabs in the plunger, for causing rotation of the shaft.
FIG. 2-10 is a cutaway perspective view of the distal end portion of the
second embodiment, showing the unwinding of the curved needle through the
aperture.
FIG. 2-11A illustrates the present invention being used to deliver the
needle to a deep wound for suturing.
FIG. 2-11B illustrates the present invention being used in arthroscopic
surgery on a knee.
FIGS. 2-12 to 2-15 illustrate a third embodiment of the present invention,
which is used to insert ring clips into tissue to hold a wound closed.
FIG. 2-12A is a cutaway view of the third embodiment, illustrating a ring
clip held therein.
FIG. 2-12B illustrates extrusion of the ring clip.
FIG. 2-12C illustrates an alternative mode of the third embodiment, adapted
for use with an extended ring clip which is held therein.
FIGS. 2-13A and 2-13B, and 2-13C and 2-13D, illustrate a marker which
indicates a first and a second direction of extrusion of the ring clip,
respectively.
FIG. 2-14 is a cross-sectional view of another alternative mode of the
third embodiment, adapted for serial extrusion of a plurality of ring
clips held therein.
FIG. 2-15A illustrates yet another mode of the third embodiment, with the
plurality of ring clips held in a magazine.
FIG. 2-15B illustrates an internal piston return spring.
FIG. 2-16A illustrates manipulation of the extended distal segment of the
ring clip of FIG. 2-12C.
FIG. 2-16B illustrates the severing of the extended distal segment of FIG.
2-16A.
FIGS. 2-17A to 2-17C illustrate various modes of a ring clip.
FIGS. 2-1A to 2-1C illustrate the first embodiment of the present
invention, a deep needle suturing apparatus 100. The apparatus 100 has a
cannula 11 and a needle delivery member which is a cannula insert 12.
Although the drawings and this description specifically show a cannula 11
and cannula insert 12 which are straight and which may be assumed to be
rigid, the cannula 11 and cannula insert 12 may be curved, or may even be
deformable to some degree, within the scope of this invention. For
example, they may be flexible and/or long enough for apparatus 100 to be
used within a channel of an endoscope (flexible or rigid), in the lumen of
a catheter, or as a catheter itself.
The cannula insert 12 has an outer dimension which allows it to fit
coaxially within the cannula 11 and move longitudinally therewithin. The
cannula 11 has a proximal end portion 11p to which are affixed cannula
handles 13 which, suitably, may be finger rings into which a surgeon may
insert his index and middle fingers. The cannula 11 has a bore 111
extending longitudinally therethrough. The bore 111 extends out the distal
end portion 11d of the cannula 11, to allow a distal end portion 12d of
the cannula insert 12 to extend distally out of the cannula 11. A cannula
insert handle 14 is affixed to the proximal end portion 12p of the cannula
insert 12. The handle 14 may, suitably, be a thumb ring through which the
surgeon may insert his thumb. By pressing on the thumb ring 14 and pulling
on the finger rings 13, the surgeon may extend the cannula insert 12
through the cannula 11 with motion 201. It will be understood that, within
the scope of this invention, various other means may be employed to extend
the cannula insert through the cannula. For example, the apparatus may
include a pistol grip with a trigger for extending the cannula insert, or
a scissor action mechanism, or the like.
The distal end portion 12d of the cannula insert 12 grasps an elastic
needle 10. In the preferred embodiment, the needle 10 is of a
pseudoelastic shape memory alloy and has an arced shape while the needle's
alloy is in a substantially austenitic phase, and the needle 10 may be
stressed into a more straight shape in which the needle's alloy enters an
at least partially more martensitic phase. When the needle 10 is held
entirely within the cannula 11, as shown in FIG. 2-1A, the needle 10 is
straightened and contains more stress-induced-martensite phase. As the
needle 10 is extruded from the distal end portion 11d of the cannula 11,
that portion of the needle 10 which extends beyond the cannula 11 returns
toward its original shape by a martensitic-to-austenitic shape memory
phase change caused by at least partial relief of the
stress-induced-martensite in the needle's alloy.
The cannula insert 12 includes a longitudinal bore 112, which may be used
to contain a suture 9 attached to the needle 10. Suitably, the bore 112
may extend longitudinally entirely through the cannula insert 12, to
permit an unlimited length of suture 9 to be puffed therethrough. Although
in FIGS. 2-1A to 2-1C the suture 9 is shown exiting through the proximal
end of the cannula insert and laterally out of the thumb ring 14, the
suture 9 may, within the scope of this invention, exit the apparatus in a
variety of manners. For example, the suture may exit through a small
aperture (not shown) in the side wall of the distal end portion of the
cannula insert, in which case bore 112 would not have to extend further
proximally and the proximal portion of cannula insert 12 would be
dimensioned such that there would be room for the suture within bore 111
(i.e., the proximal portion of cannula insert 12 could have a smaller
transverse dimension than its distal portion, or it may include a
longitudinal slot for the suture). Alternatively, the thumb ring may be
hollow, and the suture may pass directly from the interior of the cannula
insert into the interior of the thumb ring, and may exit through an
aperture (not shown) at some point about the thumb ring.
The suture may be attached to the needle in a variety of ways. For example,
the proximal end of the needle may include a hollow orifice which may be
crimped down upon an end of the suture. Alternatively, a ferrule may be
used to couple the suture to the needle. Or, a small wedge-shaped groove
may be used to pinch the suture into a slot in the proximal end of the
needle. If a more complex needle assembly is economically manufacturable,
it may be advantageous to form, into the proximal end of the needle, a
longitudinal slot or hole which may also communicate with a transverse
slot into which a knotted or thickened portion of the suture may be
positioned. Or, it may simply suffice to glue the suture onto the needle.
The distal end portion 12d of the cannula insert 12 includes a means for
holding 15, which grips the needle 10, and which is connected to the bore
112. As the distal end portion 12d is distally extended from the cannula
11 with motion 201, the means for holding 15 releases the needle 10,
permitting the surgeon to manipulate the needle 10 within the patient, to
form stitches or perform other procedures. However, if the needle 10 is
only partially extended from the cannula 11, the means for holding 15 will
not yet have released the needle 10, and the cannula insert 12 and needle
10 may be retracted into the cannula with motion 202, to allow
repositioning of the needle 10 in the patient.
FIGS. 2-2A through 2-2E illustrate various designs of the means for holding
15 formed in the distal end portion 12d of the cannula insert 12. The
distal end portion 12d is divided by a slot 16 into a plurality of end
sections 19. Each end section 19 includes a longitudinal groove 17, which
runs substantially parallel to the axis of the cannula insert 12. In one
mode, shown in FIG. 2-2A, one slot 16 divides the cannula insert 12 into
two end sections 19, each of which has a flat surface into which the
respective grooves 17 are formed. The enlargement in the slot 16, which is
formed by the adjoining groves 17, constitutes the means for holding 15.
In other modes, however, a plurality of slots may divide the distal end
portion 12d into three or more end sections 19, as shown in FIGS. 2-2B and
2-2C. If there are three or more end sections 19, the grooves 17 lie at a
centermost point of the wedge shaped end sections 19. It will be
understood that the exact cross-sectional shape of the grooves 17 is not
critical, so long as the grooves 17 remain well adapted to grasp the
needle 10. It will be understood that the slot 16 may merely be a slit cut
into the cannula insert 12, if the material of the cannula insert 12
reacts to the slit by flaring outward to allow later compression of the
distal end portion 12d.
With reference to FIGS. 2-1C and 2-4A, it will be understood how the means
for holding 15 grips the needle 10. A proximal, non-piercing end portion
10p of the needle 10 has a transverse dimension 10w, while the means for
holding 15 has a transverse dimension 15w sufficiently larger than
dimension 10w to accept the needle 10 without gripping it. The distal end
portion 12d of the cannula insert 12 has a transverse dimension 12dw
perpendicular to the slot 16, and the remainder of the cannula insert 12
has a dimension 12w which is smaller than dimension 12dw. The cannula 11
has an internal transverse dimension 11w, which is sufficiently larger
than dimension 12w to allow the cannula insert 12 to move freely
therewithin. However, because dimension 11w is smaller than dimension
12dw, in order for the distal end portion 12d of the cannula insert 12 to
fit within the cannula 11, the distal end portion 12d must compress. It
will be understood that by appropriately sizing various portions of the
bore 111, the distal end portion 12d may be caused to compress at a
determinable point along the cannula 11. The compression need not occur at
the exact distal end of the cannula.
FIGS. 2-2A to 2-2E and 2-4A illustrate embodiments of the compressible
distal end portion 12d, in which the distal end portion 12d is formed as
an integral, unitary member with the cannula insert 12. As the distal end
portion 12d is drawn into the cannula 11, the end segments 19 are pressed
toward each other, reducing the widths of the slots 16, which causes the
grooves 17 to clamp down on the needle 10. However, as shown in FIG. 2-4B,
the distal end portion 12d may simply be a separate member made of a
compressible material, such as an elastomer, with or without any slots or
end sections, which member is coupled to the cannula insert 12. In such a
mode, the entire distal end portion 12d elastically compresses onto a
needle held in its means for holding 15. In either mode, as the distal end
portion 12d of the cannula insert 12 is extended distally out of the open
end of the cannula 11, the distal end portion 12d elastically returns
toward its original shape, allowing the needle 10 to freely slip from the
means for holding 15.
FIGS. 2-2D and 2-2E may be better understood with reference to FIG. 2-1A.
It will be understood that when the needle 10 is held in the means for
holding 15, and the needle 10 is disposed entirely within the cannula 11,
the elastic properties of the needle 10 exert lateral forces upon both the
cannula 11, and the means for holding 15. The straightened needle 10
exerts lateral force on the distal end of the cannula insert 12 in the
direction shown in FIG. 2-2D by arrow 203. The needle 10 has a point which
bears on the cannula 11 at a location opposite the direction 203. By
forming the means for holding 15 in a position radially removed from the
center from the cannula insert 12, in direction 203, the needle 10 may be
held in a less stressed and less straightened configuration, without
changing the transverse dimension of the cannula 11.
The slot 16 may be radially removed from the center of the cannula insert
12, as shown in FIG. 2-2E, to divide the distal end portion 12d into two
asymmetrical end portions 19. A needle 10 held in an orientation so as to
curve opposite the direction of arrow 203 (generally upward in FIG. 2-2E)
will exert a force which is perpendicular to the slot 16 rather than along
the slot 16. This helps prevent the needle 10 from forcing its way out of
the means for holding 15 and into another position within the slot 16, and
ensures a more firm grasp on the needle 10.
FIG. 2-3 illustrates a needle release indicator formed in the distal end
portion 12d of the cannula insert 12. Near the distal end of the cannula
insert 12, a raised release signal tab 20 is formed in the distal end
portion 12d. A segment 21 immediately proximal to the tab 20 is radially
indented relative to the tab 20. Although segment 21 is shown in FIG. 2-3
as having a lateral dimension which is smaller than the remaining portions
of the cannula insert 12, this is, in various modes of the cannula insert
12, not mandatory. For example, the remaining portions of the cannula
insert 12 may be of smaller, equal, or greater lateral dimension than
segment 21, so long as the cannula insert 12 remains longitudinally
movable within the cannula 11, and so long as the means for holding 15
remains able to hold and release the needle 10.
When the distal end portion 12d of the cannula insert 12 is extended beyond
the distal end of the cannula 11, at the moment the tab 20 completely
exits the cannula 11, the distal end portion 12d snaps outward until the
segment 21 contacts the cannula 11. This produces a tangible or audible
signal to the surgeon, indicating that the cannula insert 12 is emerging
from the distal end of the cannula 11, and, depending on the placement of
the tab 20 relative to the means for holding 15, may indicate to the
surgeon that the needle 10 has just been or is about to be, released. It
will be understood that, by appropriately sizing various segments Of the
cannula 11 and by appropriately placing the tab 20, the release signal may
be made to occur at any given stage of needle extension. In an alternative
embodiment (not shown), tab 20 can be replaced by one or more elastic tabs
directed proximally which spring out as distal end portion 12d emerges
from the distal end of cannula 11.
Once the needle 10 has been released from the cannula insert 12, the
surgeon may use the needle 10 to insert running stitches or regular
stitches into the patient's tissues. Once the stitching procedure is
finished, the needle 10 must be withdrawn from the patient's body with a
minimum of trauma to the patient. The apparatus 100 of the first
embodiment can also be used in the withdrawal of the needle 10. By
maneuvering the cannula insert 12 until an end of the needle 10 enters the
means for holding 15, and then distally extending the cannula 11 onto the
cannula insert 12, the surgeon may recompress the distal end portion 12d
of the cannula insert 12, which presses the means for holding 15 onto the
needle 10. Then, by withdrawing the cannula insert 12 into the cannula 11,
the needle 10 may be restraightened and drawn entirely inside the cannula
11. The cannula 11 may then be withdrawn from the patient's body with an
absolute minimum of trauma. This same process may be used if the needle 10
is badly placed when extruded from the cannula 11. The surgeon may simply
regrasp the needle 10 in the cannula insert 12, retract the needle 10, and
re-extrude the needle 10 into a better position. The same process may even
be used repeatedly in the suturing process itself.
In order to ease the process of manipulating the cannula insert 12 back
onto the needle 10 for withdrawal, the distal end of the cannula insert 12
may include a concave face 22, as shown in FIG. 2-5. The means for holding
15 enters through the distal end of the cannula insert 12 at the deepest
point of the indented face 22. Thus, if the surgeon maneuvers the cannula
insert 12 near enough to the needle 10, so that an end of the needle 10 is
within the indented face 22, during further distalward motion of the
cannula insert 12, the indented face 22 will guide the needle 10 into the
means for holding 15.
In order to provide a more self-contained apparatus 100, the cannula insert
12 may include a means for containing a length of suture. In one mode, the
means for containing may be a suture release bobbin 25 around which a
length of suture 9 is wound, as shown in FIG. 2-6. As the surgeon uses the
needle 10 to make stitches in the patient, the suture 9 is pulled from the
distal end of the bobbin 25. By forming the bobbin 25 with a slightly
conical shape, the suture 9 may be pulled from the bobbin 25 with reduced
friction. Reducing the friction between the apparatus 100 and the suture 9
is not only desirable to make suturing easier for the surgeon, but also to
prevent accidental movement of a needle 10 which has been released within
the patient. Such unwanted movement might be caused by friction between
the suture 9 and the apparatus 100 if the apparatus 100 is moved or
inadvertently bumped by the surgeon.
FIG. 2-11A shows how the first embodiment 100 of the present invention may
be used to repair a deep wound 4 in tissues 3 and 5. The surgeon positions
the apparatus 100 near the wound to be repaired, and extrudes the needle
10 from the apparatus, as described above. The needle's piercing distal
end 10d first pierces the tissue 5 on one side of the wound 4. Then, as
the needle 10 is further extruded from the cannula 11, the needle 10
returns toward its unstressed shape. This curves the needle 10 through the
tissue 5 beneath or near the bottom of the wound 4. The piercing distal
end 10d of the needle 10 eventually penetrates and then protrudes from the
tissue 3 at the opposite side of the wound 4. The distal end 10d of the
needle may then be grasped to pull the needle through the tissue 5 and 3
to draw the suture across the wound 4. Knots may then be tied in the
suture, or the needle 10 may be repeatedly withdrawn and extruded from the
apparatus 100 to form multiple stitches. The means for holding 15 may be
used to grasp the distal end 10d of the needle during this process, in the
same manner described above for withdrawal of the needle 10. After the
distal end 10d emerges from the tissue 3, the surgeon may grasp the distal
end 10d in the cannula insert's means for holding, as described. The
surgeon may then pull the needle 10 and suture through the tissues 5 and
3. The surgeon may release the needle 10, then grasp its proximal end 10p
in the means for holding and partially or fully resheath the needle 10
inside the cannula 11 preparatory to forming another stitch.
FIG. 2-11B illustrates the first embodiment 100 of the present invention
being used in arthroscopic surgery to repair a torn meniscus 6 in a knee
7, in much the same manner. It will be understood that, because the needle
10 provides its own curving suture path as it pierces the meniscus 6, the
apparatus 100 need not be swept over any degree of motion in order to
suture the meniscus 6. The apparatus 100 is capable of performing suturing
through an entry wound which is of a minimal size. The entry wound need
only be big enough so that the apparatus 100 may slip inside the knee. In
other words, the entry wound need only be as big as the lateral dimension
of the apparatus 100.
As shown in FIG. 2-7A, a second embodiment of the present invention is an
apparatus 200 which extrudes a needle 10 laterally rather than distally.
The second embodiment 200 includes a cannula 30 which is substantially
similar to the cannula of the first embodiment. Apparatus 200, which is
preferably rigid, can be long and/or flexible enough for apparatus 200 to
be used in a channel of an endoscope (flexible or rigid), in the lumen of
a catheter, or as a catheter itself. However, the second embodiment's
cannula 30 does not have an open distal end. Rather, the second embodiment
200 extrudes the needle 10 through an aperture 31 which is located through
a side wall of the cannula 30 near its distal end. In this application, it
is intended that the term "adjacent the distal end", when applied to the
location of the aperture or of other equivalent means, indicates that the
aperture may open either through the side wall of the cannula or actually
through the distal end of the cannula.
Inside its distal end, the cannula 30 includes a pivot 34, about which a
shaft 29 rotates. The distal end portion of the shaft 29 is a spool
portion 29d about which the needle 10 is wrapped. When used with the
second embodiment 200, the needle 10 is stressed into a more curved,
rather than a more straightened, shape when disposed within the apparatus.
Relief of the stress in needle 10 held in the more curved configuration,
then, results in the needle 10 returning toward its more straight shape
which may be a curve suitable for suturing.
Much of the remainder of the shaft 29 includes spiral grooves 27. A plunger
28 is disposed about the shaft 29 and within the cannula 30, and has tabs
26 which engage the spiral grooves 27 of the shaft 29. When the plunger 28
is moved into the cannula 30, the tabs 26 and grooves 27 impart rotating
motion 210 to the shaft 29 and needle 10. When the plunger 28 is
withdrawn, the shaft 29 rotates in the opposite direction.
FIG. 2-9 is a cross sectional view of the apparatus 200, taken across line
9--9 of FIG. 2-7A, and illustrates the special relationship between the
cannula 30, the plunger 28 with its tabs 26, and the shaft 29 with its
spiral grooves 27. As will be understood, a functionally identical
equivalent may be constructed by affixing the tabs 26 to the shaft 29, and
adapting the plunger 28 with the spiral groves 27. As further shown in
FIG. 2-9, the groove-engaging tabs 26 of the plunger 28 may also extend
outward from the plunger 28, and the inner surface of the cannula 30 may
also be adapted with grooves 72. By forming the grooves 72 in the cannula
30 to run substantially linear to the axis of the cannula 30, the plunger
28 will be prevented from rotating upon insertion into and withdrawal from
the cannula 30.
As shown in FIG. 2-7B, the tabs 26 may be constructed as a part of the
cannula 30. The thumb ring 14 is coupled to the plunger 28 by a swiveling
means. In one mode, the swiveling means may be the simple snap-lock
mechanism 28c shown in FIG. 2-7D, which is held in place by an end cap
28b. In this mode, the shaft 29 slidably engages the plunger 28 by any
non-circular cross-section instead of having spiralled grooves.
With reference to FIGS. 2-7C and 2-7E, it will be understood that the exact
means for imparting rotation to the shaft 29 may be formed in a variety of
ways within the scope of this invention. For example, the tabs and grooves
may be eliminated by simply forming the plunger 28 of a spiral-twisted rod
of square cross-section, and providing the cannula 30 with an appropriate
end cap 57 which has an opening suited for permitting the plunger 28 to
pass therethrough only by appropriate rotation. Other non-circular
cross-sections are, of course, within the scope of this invention. Again,
shaft 29 slidably engages plunger 28 by any non-circular cross-section
instead of having spiralled grooves. It is to be understood that any
suitable activating means, such as syringe-plunger mechanisms, slidings
mechanisms, pistol grip action mechanisms, scissor action mechanisms or
the like can be used to depress plunger 28 into cannula 30.
With reference again to FIG. 2-7A, the shaft 29 may contain a repository 32
which is a means for containing a length of suture 9. The shaft 29
includes a needle stop 24, which prevents the needle 10 from rotating
backward relative to the shaft 29. In one embodiment, the needle stop 24
may simply be a lip on one side of the repository 32, which lip forms a
means for abutting a non-piercing end of the needle 10.
FIG. 2-8 illustrates an alternative mode of the repository 32, in which the
repository may be a bobbin 33 which contains a length of suture. The
bobbin 33 rotates freely about the shaft 29 with motion 205. This, too,
reduces friction between the suture and the apparatus 200, to prevent
unwanted movement of the needle 10 via the suture, once the needle 10 has
been completely extruded from the cannula 30.
FIG. 2-10 is a cutaway cross-sectional view of the distal end portion of
the second embodiment 200, and illustrates the unwinding of the needle 10
through the aperture 31. The aperture 31 must have a dimension sufficient
to allow the needle 10 to freely pass therethrough in its entirety without
binding. As the spool portion 29d of the shaft 29 rotates relative to the
cannula 30, the needle 10 unwinds through the aperture 31 and returns to
its unstressed shape. It will be understood that the alternative modes
shown in FIGS. 2-7B to 2-7E are not complete, and must include appropriate
components at their distal ends, much like those shown in FIG. 2-7A.
As will be understood, the second embodiment 200 may be used in a
substantially similar fashion as described for the first embodiment of the
deep needle suturing apparatus 100 with reference to FIGS. 2-11A and
2-11B, above. The second embodiment 200, however, may be used to provide
surgical access to various suturing sites not accessible with the first
embodiment.
In some surgical procedures, stitches are not implanted in a wound. In a
third embodiment 300 of the present invention, illustrated in FIGS.
2-12A-2-12C, the unstressed shape of the needle may be substantially
circular to form the needle into a ring clip 8. Only after the wound has
healed are the ring clips removed, if at all.
FIG. 2-12A shows the third embodiment 300 of the present invention, adapted
for inserting ring clips 8 (which can be hollow or solid) rather than
needles. The third embodiment 300 includes a cannula or cylinder 35 which
is substantially similar to the cannula of the first embodiment. Apparatus
300, which is preferably rigid, can be long and/or flexible enough for
apparatus 300 to be used in a channel of an endoscope (flexible or rigid),
in the lumen of a catheter, or as a catheter itself. However, the cylinder
35 has an internal dimension which may be more similar to the outer
dimension of the wire of the ring clip 8 than is the inner dimension of
the first embodiment's cannula to the needle. By forming both the wire
from which the ring clip is made and the internal bore of the cylinder to
have a non-circular cross-section, the ring clip may be prevented from
rotating within the bore. The third embodiment 300 further includes a
piston 36, whose transverse dimension is substantially equal to the inner
dimension of the cylinder 35. The piston 36 need not necessarily contain
any means for grasping the ring clip 8, as it is only used to extrude the
ring clip 8 from the cylinder 35. However, adaptations of the third
embodiment 300 which provide means for holding and retracting the ring
clip 8, similar to those provided for holding and retracting the needle in
the first embodiment, are certainly within the scope of this invention.
The ring clip 8 is disposed within the cylinder 35, with its distal end 8d
facing toward the open distal end of the cylinder 35. The piston 36 is
disposed within the cylinder 35, with the distal end of the piston 36
abutting the proximal end 8p of the ring clip 8. Insertion of the piston
36 through the cylinder 35 with motion 206 expels the ring clip 8 from the
cylinder 35 as shown in FIG. 2-12B. As the ring clip 8 is expelled, it
returns to its unstressed shape with coiling motion 207, as described
above for the needle of the first embodiment. Suitably, the ring clip 8
may have an unstressed shape which is substantially circular, in order
that it may pass through a patient's soft tissues with a minimum of
lateral pressure, to cause a minimum of structural damage to the tissues.
The third embodiment 300 (as well as any of the embodiments of this
invention) may be adapted with at least one marker means 55. The marker 55
may be, suitably, a raised or embossed portion of the cylinder 35, or may
simply be printed thereon. With the ring clip 8 loaded into the cylinder
35 in an appropriate orientation, the marker 55 will indicate the
direction in which the ring clip 8 will curl when extruded. This aids the
surgeon in properly clipping a wound. It will be understood that any of
the various embodiments described herein may also be advantageously
adapted with a suitable marker means. FIGS. 2-13A-2-13B, and FIGS.
2-13C-2-13D, illustrate proper alignment of the marker 55 indicating two
respective directions of extrusion of a ring clip 8. The respective
positions of the marker 55 in FIGS. 2-13A or 2-13C indicate that the ring
clip 8 will exit the cylinder 35 in the direction as shown in FIGS. 2-13B
or 2-13D, respectively. Marker 55 may be positioned at any suitable
location along the cylinder. More that one marker may be present.
In another mode, shown in FIGS. 2-12C and 2-16A, the ring clip 8 includes
an extended proximal segment 49, whose unstressed shape is relatively
straight. This proximal segment 49 may be grasped by the surgeon in any
manner and manipulated, in order to adjust the ring clip 8 within the soft
tissues. In this mode, the piston 36 has an enlarged diameter and includes
a bore 37 extending into the piston 36. Adapting the piston 36 with the
bore 37 allows the third embodiment 300 to contain the lengthened and
extended ring clip 8. This obviates the need to lengthen the cylinder 35,
making the apparatus 300 easier for the surgeon to handle. As shown in
FIG. 2-16B, after the surgeon has manipulated the extended ring clip 8,
the extended end segment 49 may be removed by any conventional method,
such as cutting it off with wire cutters. It will be understood that the
proximal segment 49 need not be of an elastic material, but may be any
conventional material affixed to the elastic segment 8 in order to
minimize the cost of the apparatus 300.
The cylinder and piston of the third embodiment of the apparatus may be
used with a variety of different ring clips, such as are shown in FIGS.
2-17A-2-17C. As shown in FIG. 2-17A, the ring clip 8 may be formed such
that, in its unstressed configuration, its distal end 8d and proximal end
8p come into end-to-end abutting alignment. Alternatively, as shown in
FIG. 2-17B, the ends 8d and 8p may come into side-by-side overlapping
alignment. Locking of the ring clip may be permitted by having a small
barb or barbs (not shown) on end 8d which fit(s) into a recess or recesses
(also not shown) on end 8p or vice versa.
A slightly modified ring clip may include a proximal coupling hook 8ph. In
such a configuration, in the ring clip's unstressed configuration, the
hook 8ph remains somewhat separated from the piercing end 8d, such that
the ring clip does not form a complete circle. The surgeon may stress the
ring clip into a tighter arc, and engage the hook 8ph with the piercing
end 8d, as shown. The elasticity in the ring clip 8 will cause the hook
8ph to remain engaged under mechanical stress. Such a mode of the ring
clip is taught in U.S. Pat. No. 5,002,563 (Pyka et al).
As shown in FIG. 2-14, the third embodiment 300 may have a lengthened
cylinder 35, within which may be disposed a plurality Of ring clips 8a-8n.
Injection of the piston 36 through the cylinder 35 then causes serial
extrusion of the ring clips 8a-8n.
Serial extrusion of ring clips 8a-8n may also be accomplished by adapting
the third embodiment 300 as shown in FIGS. 2-15A or 2-15B. In this mode,
the third embodiment 300 includes a magazine 38 which holds the plurality
of ring clips 8a-8n. The magazine 38 includes a magazine spring 39, which
presses on the ring clips 8a-8n to keep them in their stressed and more
straightened shape, and which introduces them serially into the cylinder
35, in position for extrusion by the piston 36. The magazine 38 may be
separately attachable, and may also be refillable. It will be understood
that any suitable means may be used to keep the plurality of ring clips in
any favored orientation, if it is desired that they exit the cylinder 35
in a predetermined orientation of curvature. For example, the ring clips
8a-8n may be formed of a rectangular cross section, or they may be
releasably glued together, to prevent their rotation, within the magazine
38, away from their preferred orientation.
The third embodiment 300 may further be adapted with a piston return spring
40, which is compressed upon injection of the piston 36, and which
automatically returns the piston 36 to a position allowing introduction of
the next ring clip into the cylinder 35. As shown in FIG. 2-15B, the
piston return spring 40 may be disposed within the cylinder 35. In this
mode, the cylinder 35 includes an enlarged chamber 41, within which the
spring 40 is disposed. The piston 36 may include an enlarged segment 42,
which is disposed within the cylinder 35, and which is kept inside the
cylinder 35 by an end cap 43 on the cylinder 35. This maintains the
apparatus 300 as a more integral unit, and prevents the complete
withdrawal of the piston 36 from the cylinder 35. This also allows for a
precompressed piston return spring 40 to be used, which provides greater
return strength and speed for the piston 36. It is to be understood that
any of the embodiment of this invention may be activated by any suitable
activating means, such as syringe-plunger mechanisms, slidings mechanisms,
pistol grip action mechanisms, scissor action mechanisms or the like.
A third form of the present invention provides an endoscopic or
laparoscopic surgical device which provides an internal drape, and
facilitates tissue collection. The surgical device comprises a housing
having an axial bore with a distal deployment opening; and a barrier
member which is constrainable within the axial bore. The barrier member
comprises a loop of elastically recoverable material, preferably a shape
memory alloy, and a barrier membrane loosely spanning the loop. Remote
means are provided to project and retract, and optionally to rotate, the
barrier member relative to the distal end of the housing. A preferred
embodiment uses a shape memory alloy material, especially a pseudoelastic
shape memory alloy material, and more preferably a superelastic shape
memory alloy material.
The barrier member is moveable between a first position wherein the barrier
member is constrained within the housing, and a second position wherein
the barrier member is extended past the distal deployment opening of the
housing, and assumes an expanded shape. In the expanded shape, the barrier
member acts as a surgical drape and/or as a surgical collector. The
barrier member is preferably moveable to a third position wherein the
barrier member is partially or fully retracted, and at least a portion of
it is constrained within the housing.
The loop of elastically recoverable material may be partially or wholly
formed of elastically recoverable material. Thus for example two or more
parts of the loop, eg two substantially semi-circular halves of the loop,
may be connected to each other by another member which may or may not be
elastically recoverable. In one embodiment two or more elastically
recoverable parts of the loop are connected to each other by a flexible
heat-shrinkable sleeve, which preferably comprises a polymeric material.
In this case the elastically recoverable parts may comprise a shape memory
alloy as described hereinbefore, or traditional resiliently deformable
materials such as spring metals. The heat recoverable connecting sleeve,
being flexible can bend eg by acting as a hinge to allow the loop parts to
fold together to be compressed into the housing, and also to spring apart
when extended from the housing. The connecting member may itself be
resilient, causing the arms of the loop to spring apart when the loop is
deployed outside the housing.
In one advantageous embodiment the connecting member, can be removed to
release the barrier membrane, eg the bag or drape, spanning the loop.
In preferred embodiments according to the invention, especially where the
barrier member is acting as a collecting pouch, a bushing is included in
the housing. This bushing is arranged to be pushed out from the distal end
of the housing at the same time or after the barrier member is deployed,
and then to snap against the outside of the distal end of the housing.
Since it is snapped against the housing the bushing can not then be
withdrawn back into the housing. This hollow bushing may serve two
functions. Firstly, the dimensions of the hollow bushing are preferably
such that it allows complete withdrawal back into the housing of the
elastically deformable loop, but not a filled barrier membrane, which may
now be of larger volume, being filled, for example, with body samples.
Thus the bushing ensures that the barrier member remains suspended outside
the housing, as desired for some applications. Secondly the bushing is
preferably shaped to provide a smooth entrance so that the barrier member
is not torn by contact with the ends of the housing.
In the above embodiments, where a loop or a frame of an elastically
deformable material is constrained within a housing such as a cannula or
the like it is particularly advantageous to modify the design of the loop
in order to minimize or, to suppress any possible risk of plastic
deformation. Therefore in preferred embodiments the elastically deformable
loop preferably comprises a necked portion, preferably towards the distal
end of the loop. The "necked portion" is formed where the sides or arms of
the loop come towards each other and then divert outwards of the loop
before turning towards each other again to join to each other. A bulbous
portion, or second loop portion, is thereby formed adjacent to the main
loop portion. The bulbous portion is preferably of significantly smaller
dimensions than the main loop portion. The advantage of the necked-loop
design is that when the loop is constrained within the housing any severe
deformation is absorbed by the necked region and therefore the risk of any
plastic deformation to the main loop portion is substantially eliminated
or at least minimized.
The necked portion may, for example, be formed in the following two ways.
First the sides of the loop may come toward each other, overlap, and then
curve outwards in the opposite sense to join to each other. In this case
the overall shape is a double loop configuration, similar to a figure "8".
In the second case the sides of the loop divert outwards without
overlapping to form a bulbous region, or "nipple" configuration adjacent
the main loop.
One advantage of the preferred necked-loop configuration is that it allows
severe constraints to be put on the elastically deformable loop without
introducing any plastic deformation into the main body of the loop. This
allows smaller diameter housings to be used to constrain the loop than
would be possible without the necked configuration. This can be
particularly advantageous, for example, in less invasive surgery. The
design also allows the thickness of the loop to be increased without
risking plastic deformation. Thus the loop rigidity may be increased which
may be advantageous for some applications, especially for example where
large bops are to be used.
FIG. 3-1 is a view of an unexpanded barrier device (not shown) within a
housing. FIG. 3-2 through FIG. 3-5 are progressive cross-sectional views
through line a--a of FIG. 3-1, showing the use of the device of FIG. 3-1.
The figures show, respectively, FIG. 3-2, constrained; FIG. 3--3, expanded
(memory); FIG. 3-4, pouched; and FIG. 3-5, withdrawal configurations.
FIG. 3-6 shows alternate embodiments of the device of FIG. 3-1 through line
b--b.
FIG. 3-7 and FIG. 3-8 show alternate embodiments of the barrier member in
the expanded (memory) configuration.
FIG. 3-9 shows cross-sectional embodiments through line b--b of FIG. 37.
FIGS. 3-10, 3-11 and 3-12 detail alternate expanded loop configurations.
FIG. 3-13 is a schematic representation of another embodiment of a device
for deploying an internal drape, and
FIGS. 3-14 and 3-15 are schematic representations of yet another embodiment
of device for deploying an internal bag, showing the device before and
after withdrawal of the drape into the shaft of the instrument.
FIGS. 3-16 to 3-18 illustrate the use of a bushing which can be used with
any of embodiments 3-1 to 3-15.
FIGS. 3-19 to 3-22 illustrate a necked-loop configuration which can be
incorporated in any of the embodiments, illustrated in FIGS. 3-1 to 3-18.
During surgery, especially "least invasive surgery" (LIS), it is frequently
necessary to remove diseased tissue. This tissue may be infected, contain
inflammatory secretions (e.g., bile), or contain tumor cells. In any of
these situations it is desirable to perform surgery without contaminating
surrounding healthy tissues with any of the diseased tissue. Expandable
internal barriers of this invention minimize or prevent such
contamination. The expandable barrier member comprises (a) a flexible
membrane which loosely spans (b) a loop of elastically deformable
material. The elastically deformable loop is preferably a pseudoelastic
shape memory alloy which defines an expanded loop in its "memory" shape.
The expandable barrier is constrained within a housing, and the deployment
end of the housing is placed within a body. The barrier is deployed from
the housing and expands to its memory shape.
The barrier can be placed under diseased tissue, so that undesired
materials spill into the barrier by gravity and/or irrigation flow,
without contaminating surrounding tissues. The undesired materials can be
aspirated from the surface of the barrier prior to withdrawal of the
device. Alternatively, the barrier is placed so that it substantially
surrounds and encloses the diseased tissue and sequesters it from healthy
tissue during surgery. The tissue sample is severed (if necessary). In a
preferred embodiment, when the elastically deformable loop is first
withdrawn back into the housing, the barrier membrane remains suspended
outside the housing. The upper edge of the barrier membrane closes to form
a pouch as the elastically deformable loop is retracted into the housing.
Within the pouch is a tissue sample or other material which has been
enclosed by the membrane. The housing, barrier and enclosed materials are
removed from the patient.
The Figures are drawn for purposes of clarity and are not drawn to scale.
Like numbers represent like structures.
FIG. 3-1 is a lateral external view of a device according to the subject
invention. The housing 10 includes a deployment end 12 which is inserted
into the patient and which houses the expandable barrier member (not
shown) in a constrained configuration; a shaft portion 14 which may be
partially or completely inserted within the patient body; and an actuator
end 16 opposite the deployment end, which is retained substantially
outside the patient. The housing 10 can be flexible or rigid, and its
rigidity can vary along its length. A remote actuator means 18 is used to
project and/or retract, and, optionally, to rotate the barrier member
relative to the distal deployment opening 24.
FIGS. 3-2 through 3-5 show the use of a device of this invention to obtain
a tissue sample. They are simplified cross sectional representations of
the device shown in FIG. 3-1, the cross section being taken along line
a--a. In use, the device is partially inserted into a human or animal
patient (not shown). The housing can be inserted directly into a patient,
or the device can be emplaced using an instrument channel of a standard
endoscope, laparoscope, catheter, or the like.
FIG. 3-2 shows a cross-section of the device of FIG. 3-1 with the
expandable barrier member 22 in a first, constrained configuration.
The housing 10 is preferably an elongate sheath, having an axial bore 20
therethrough, the axial bore being sized to receive the expandable barrier
member 22 in a constrained configuration. The axial bore 20 opens to the
environment at the deployment opening 24. In one embodiment (not shown),
the axial bore also opens to the environment at the activator opening 26,
and access for additional laparoscopic or endoscopic devices, and/or fluid
access or withdrawal, is provided. A seal (not shown) may be added at the
activator opening 26, to minimize or prevent fluid (i.e., liquid or gas)
leakage.
The specific configuration and dimensions of the axial bore 20 will vary
with the use of the device, the parameters of the barrier member 22, and
whether access for additional laparoscopic or endoscopic devices is
provided. In general the axial bore 20 will have an internal diameter of
from less than about 0.3 cm to about 2 cm or greater, preferably from
about 0.25 cm to about 2.5 cm. In one embodiment (not shown), the axial
bore comprises a working channel of an endoscope. Such an endoscope can
also provide surgical implements such as lasers, scalpels, irrigation and
aspiration means, visualization means, and the like.
The outer diameter of the housing 10 will vary with the application, the
size of the expandable barrier, and whether additional working channels
are included in the device. The housing in a laparoscopic device will have
a diameter of from less than about 1 mm to about 3 cm or greater,
preferably from about 0.4 cm to about 1.5 cm. The length of laparoscopic
devices will be from less than about 10 cm to about 30 cm or greater, more
generally from about 20 cm to about 30 cm. The housing 10 of a device
intended for endoscopic use will have a diameter of from less than about 1
mm to about 3 cm or greater. The length of endoscopic devices will be from
less than about 10 cm to about 1 meter or greater.
The barrier member 22 is extended through the deployment opening 24
remotely. The barrier member 22 can be attached through the actuator
opening 26 of the housing 10 by a connecting means 28. The connecting
means 28 can be, for example, soldered or otherwise affixed to the barrier
member 22, as shown. Alternatively, it can be a continuation of the
elastic material used in forming the elastically deformable loop 36. In
the shown configuration, the barrier member 22 is attached to the remote
actuator means 18 by the connecting means 28. Longitudinal axial movement
of the activator means 18 relative to the housing 10 causes the barrier
member 22 to be extended from, or retracted into, the housing 10, via the
deployment opening 24. Rotational movement of the activator means 18
relative to the housing 10 causes the barrier member 22 to be rotated. If
rotational movement is not desirable, a means to prevent rotation can be
employed.
In the depicted configurations, the remote actuator means 18 slidably
engages the activator opening 26. The remote actuator means 18 can be an
extension of the elastically deformable loop 36, or of the connecting
means 28, and be substantially independent of the housing 10.
Alternatively, the remote actuator means 18 can be connected to the
connecting means 28.
The housing 10 includes, or provides integration with, a surgical handling
apparatus to deploy and retract the barrier member. In one embodiment, as
shown, two finger rings 30 are part of the actuator end 16. An additional
thumb ring 32 is part of the remote actuator means 18. These rings are for
ease of handling. Knobs or ridges, for example, can be provided for ease
of integration with a separate actuator means (not shown). Suitable
actuator means include slider mechanisms, pistol grip or thumb actuated
mechanisms, scissors handles, and syringe-plunger mechanisms (similar to
the configuration shown in FIGS. 3-2 through 3-6). These and others are
well known to the art. The specific type of actuator mechanism is
generally determined by the personal preference of the surgeon.
In use, the deployment end 12, and possibly the shaft portion 14, is
inserted into the patient. The housing can be inserted directly into the
patient, or it can be introduced using the instrument channel of a
standard LIS device. The deployment end 12 possesses lateral integrity
such that it is not significantly deformed by the pressure exerted by the
constrained barrier member 22. In a device having a rigid housing (the
usual case for a laparoscopic device), the deployment end 12 of the
housing can be integral to the shaft portion 14 of the housing, such that
there is no obvious demarcation between the functional zones. When a
device of this invention functions as a catheter (typical with endoscopic
use) and there is little lateral support, the deployment end 12 may
require reinforcement to provide consistent constraint of the expandable
barrier member.
The shaft portion 14 of the housing is located between the actuator
(non-inserted) end 16 and the deployment (inserted) end 12 of the device.
The shaft portion 14 of the housing may be inserted into the patient (not
shown) partially or completely. The shaft portion 14 of a device which is
used in laparoscopy must have sufficient structural integrity that it is
easily inserted through a surgical opening into the body of the patient
without undue deformation. Materials with sufficient structural rigidity
include stainless steel and rigid polymeric materials such as plastics.
The material of the shaft portion 14, and the material of the deployment
end 12, can be the same, or can have different physical properties. For
example, the shaft portion 14 of an expandable barrier device housing used
in endoscopic surgery will generally be flexible, to allow insertion
through naturally occurring orifices, ducts, and/or passages, or to allow
insertion through the working channel of an endoscope. Suitable polymeric
material includes polytetrafluoroethylene, polyurethane, polyethylene,
Teflon, and the like. The material of such a flexible housing may be
reinforced at the deployment end 12 with fibers, rings, or longitudinal
ribs, for example, to enable it to withstand the forces exerted on it by
the barrier member 22 while it is constrained within and deformed by the
housing.
The barrier member 22 has two components: the barrier membrane 34, and the
elastically deformable loop 36.
When expanded, the barrier member 22 can have a diameter of from about 1 cm
or less to about 5 cm or greater, more generally from about 2 cm to about
4 cm. The barrier membrane 34 spans the elastically deformable loop 36
loosely, forming a rounded plate or bowl. The depth of arc described by
the barrier membrane 34 when suspended from the elastically deformable
loop 36 is from less than about 1 cm to about 7 cm or greater. In general,
the preferred depth of the pouch formed by the barrier membrane 34 will be
less when the barrier membrane 34 is used primarily as a tissue protecting
surgical drape, and will be correspondingly greater when the barrier
membrane is used as a pouch to collect tissue or to remove tissue in toto
from the surgery site. In those embodiments in which a relatively deep
bowl-like pouch is present, it may be desirable to reinforce the barrier
membrane. Reinforcing stays or ribs, made of, for example, plastic,
thickened barrier membrane material, or a shape memory alloy, provide
reinforcement, and assist the barrier membrane to deploy fully into the
desired shape.
The barrier member 22 is compressed and loaded within the axial bore 20. In
this constrained configuration, the barrier device can be sterilized,
packaged and stored for later use. Preferably at least one expandable
barrier device is available during surgery: when needed, the surgeon Can
visually assess the size of the barrier member necessary for tissue
protection and/or collection, and select an appropriate expandable barrier
device.
When constrained, the barrier membrane 34 is collapsed, and may be furled
around the elastically deformed loop 36. The barrier membrane is
preferably made of a flexible and impermeable biocompatible material. The
composition of the barrier membrane will reflect the specific use of the
expandable barrier. The barrier membrane is sufficiently thin that it can
be folded or gathered, together with the elastically deformable loop, to
fit within the axial bore 20.
In one preferred embodiment, the barrier membrane material is substantially
impermeable to body fluids and other liquids, such as normal saline
solution, which might be present during surgical procedures. The thickness
of the membrane is sufficient to provide an effective barrier to noxious
or contaminated materials such as bile, spillage from inflamed or infected
tissues, or tumor cells. Suitable materials include polyethylene,
polyvinyl chloride, urethane, silicone rubber, and the like.
In an alternate preferred embodiment, the barrier membrane material is
substantially impermeable to tissue samples, but is generally permeable to
body fluids and other liquids, such as normal saline solution, which might
be present during surgical procedures. In this embodiment, the barrier
membrane material can be a net, web, or grid. Suitable materials include
perforated, webbed or netted polyethylene, polyvinyl chloride, urethane,
silicone rubber, and the like. A similar construct can be made of, or
contain, shape memory materials.
The elastically deformable loop 36 is a wire, or a strip of elastic
material. The term "elastic material" is used herein to mean a metallic
material that has spring-like properties, that is, it is capable of being
deformed by an applied stress and then springing back, or recovering, to
or toward its original unstressed shape or configuration when the stress
is removed. The elastic material is preferably highly elastic. The
material are metallic. The use of metals such as shape memory alloys is
preferred. Shape memory alloys that exhibit pseudoelasticity, in
particular superelasticity, are especially preferred. The elastic
materials herein exhibit greater than 1% elastic deformation, more
generally greater than 2% elastic deformation. Preferably, the elastic
materials herein exhibit greater than 3% elastic deformation, more
preferably greater than 4% elastic deformation.
FIG. 3--3 shows the device of FIG. 3-2 in an expanded position. The remote
actuator means 18 has been moved distally along the axial bore 20. The
elastically deformable loop 36 extends past the confines of the deployment
opening 24. Once the elastically deformable loop 36 is released from the
compression of the housing 10, the loop regains its Unconstrained, memory,
shape and the barrier member 22 attains its deployed configuration. While
the elastically deformable loop 36 is shown as generally circular or oval,
other shapes are also possible. Elliptical, rounded, square, and irregular
shapes are also possible, and may be desirable for a particular
application.
The barrier membrane 34 is connected to the elastically deformable loop 36.
As the loop expands, the barrier membrane 34 unfurls to form a generally
plate-like or bowl-like enclosure having a mouth 38. The perimeter, or the
mouth 38, of the barrier membrane 34 is defined by the intersection of the
elastically deformable loop 36 and the barrier membrane 34.
The more bowl-like configuration, shown in FIG. 3-3, is generally preferred
when the device is used to collect or retrieve tissue samples. In use, the
expanded barrier member 22 is suspended internally at or near the surgical
site. The barrier can be manipulated to underlie the surgical site, so
that fluids or other materials which are released at the surgical site
flow gently downhill into the expandable barrier by means of irrigation
flow and/or gravity. When the barrier membrane 34 is bowl-like, it can
substantially contain a tissue sample 40 to be excised and removed during
surgery.
FIG. 3-4 shows the device of FIG. 3--3 in a pouched configuration,
partially between the expanded configuration of FIG. 3--3 and the
withdrawal configuration of FIG. 3-5. The remote actuator means 18 has
been moved proximally along the inside of the axial bore 20. The
elastically deformable loop 36 extends only partially past the confines of
the deployment opening 24, and constraining force of the housing 10 has
forced the elastically deformable loop 36 into a deformed,
semi-constrained shape. The barrier membrane 34 can preferably slide
relative to the elastically deformable loop 36. The barrier membrane 34 is
preferably not retracted into the housing 10 with the elastically
deformable loop 36, and remains substantially outside of the housing 10.
As the elastically deformable loop 36 is withdrawn into the housing 10,
the barrier membrane 34 catches on the deployment opening 24 of the
deployment end 12 of the housing 10. Therefore, the diameter of the mouth
38 of the barrier membrane 34 becomes reduced as compared to the expanded
configuration shown in FIG. 3--3, and the barrier membrane 34 forms a
pouch. The tissue sample 40 is substantially enclosed in the pouch.
FIG. 3-5 shows the device of FIG. 3-4 in a configuration for withdrawal
from the body. The remote actuator means 18 has been moved further along
the axial bore 20 in the proximal direction, and is in approximately the
position from which it started. The elastically deformable loop 36 is
substantially fully retracted into the axial bore 20, and constraint of
the housing 10 has deformed the elastically deformable loop 36 to fit
within the axial bore 20. The mouth 38 of the barrier membrane 34 is
retracted into the housing 10 with the elastically deformable loop 36,
preventing any undesired loss of tissue or fluids from within the pouch.
The body of the barrier membrane 34, containing the tissue sample 40,
remains substantially outside of the housing 10, In this configuration the
device is withdrawn. As the filled pouch of the barrier membrane 34 is
generally larger than the deployment opening 24, there is a tendency for
the barrier membrane 34 to seal against the deployment opening 24 of the
housing 10. This tendency can be enhanced by placing a seal or gasket
means (not shown) at the deployment opening 24.
While the demonstration of the device as shown In FIG. 3-1 through FIG. 3-5
is representative of one embodiment of a device of this invention, other
embodiments are also within the scope of the invention. For example, in an
alternate embodiment, not shown, the barrier membrane 34 is adhered to the
elastically deformable loop 36, so that as the mouth of the barrier
membrane 34 is withdrawn into the housing 10 it is only collapsed
transversely as the elastically deformable loop 36 is withdrawn into and
contained within the axial bore. In yet another embodiment, the barrier
membrane and tissue sample are completely withdrawn into the housing for
removal from the body.
The pouched barrier membrane can provide a transfer means for tissues which
have been removed from a patient and are to be delivered, for example, to
a pathology laboratory. The entire barrier device can be delivered, or the
distal end of the device including the pouched barrier membrane can be
separated from the rest of the device and delivered (not shown). If such a
transfer is desired, the barrier membrane can be lined with, can contain,
or can be filled with a tissue preservative.
FIG. 3-6 shows representative embodiments of a cross-section through the
housing, taken along line b--b of FIG. 3-1. A barrier membrane would
normally be enclosed within the housing in a folded, bunched, or furled
configuration. For simplicity, however, the barrier membrane is not shown.
FIG. 3-6A shows a housing 110 having a circular cross-section. This is a
preferred cross-section for an expandable barrier device of this
invention. A circular housing cross-section has the advantage of being
deformable in any radial direction. A circular housing cross-section also
permits delivery of an expandable barrier of this invention through a
standard laparoscopic trocar, or through the instrument channel of a
standard endoscope. However, other cross-sections may be preferable.
Within the axial bore 120 is the elastically deformable loop 136, which has
been constrained to fit within the axial bore 120. The elastically
deformable loop 136 is shown having an elongated oval cross-sectional
shape. This is a preferred cross-sectional shape, as it permits structural
rigidity of the expanded loop in a direction perpendicular to the general
plane of the loop, but does not compromise the lateral compressibility of
the loop within the general plane of the loop. However, the elastically
deformable loop 136 can have any appropriate cross-sectional shape.
The axial bore 120 can provide access for auxiliary implements such as an
electrocautery device, laser, knife, probe, or other surgical implement,
an imaging means, or an irrigation or aspiration means. Auxiliary
implements can be an integral pad of the device as manufactured, or can be
introduced as needed through the axial bore 120.
FIG. 3-6B shows a housing 110 which has an oval cross-sectional shape.
Within the axial bore 120 is the elastically deformable loop 136, which
has been constrained to fit within the axial bore 120. The elastically
deformable loop 136 is shown with a rounded cross-sectional shape. A lumen
142 is present. The lumen 142 can have any desired cross-sectional shape.
The lumen 142 is used to introduce auxiliary implements to the surgical
site. Auxiliary implements can include, for example, an electrocautery
device, laser, knife, probe, or other surgical implement, an imaging
means, or an irrigation or aspiration means. Auxiliary implements can be
an integral part of the device as manufactured, or can be introduced as
needed through a provided lumen 142.
FIG. 3-6C represents an embodiment in which a cautery wire 144 is provided
as an integral part of the expandable barrier device. Various cautery
wires are known in the art and are suitable for use with this invention.
In the pictured embodiment, the cautery wire 144 is a loop through which
electrical current can flow. It is located adjacent to the mouth of the
barrier membrane when both the expandable barrier and the cautery wire are
deployed. Insulation 146 can be provided around sections of the cautery
wire, for protection of tissues and of the housing. The cautery wire 144
is used to sever and/or cauterize tissues, which are preferably collected
within the expanded barrier member. The deployment and retraction of the
cautery wire can be controlled using the same actuator as that which
deploys and retracts the expandable barrier element. Alternatively, a
second actuator mechanism can be supplied for deployment of the cautery
wire.
The cautery device can be made of any suitable material. If the cautery
device is rigid, then the size of the cautery device is either limited to
the size of the lumen 142, or it protrudes from the deployment end of the
lumen at all times. However, the cautery wire can comprise an elastic
material. In a preferred embodiment, the cautery wire is a loop of wire,
and the loop is constrained within the lumen 142 while the expandable
barrier device is placed within the body. In an alternate embodiment, the
cautery wire is a hook-shaped span of elastic material which can be
linearly constrained within the lumen 142.
It has been discovered that an improved cautery device can be made of a
shape memory alloy. The use of an SMA which exhibits pseudoelasticity has
the advantage that the amount of elastic deformation that is available is
large compared with that available from many other electrically conductive
materials. The large amount of elastic deformation of the alloy allows the
loop to have a small transverse dimension when it is constrained within a
housing.
FIG. 3-6D shows the cautery wire 144 located within the elastically
deformable loop 136. This arrangement permits the cautery wire 144 to be
within the mouth of the barrier membrane. It also permits the cautery wire
and the elastically deformable loop to be contained in the same lumen of
the housing. The deployment of the cautery wire can be controlled using
the same actuator as that which deploys and retracts the expandable
barrier element. Alternatively, a second actuator mechanism can be
supplied for deployment of the cautery wire. Other embodiments (not shown)
include adhering the cautery wire to the mouth portion of the expandable
barrier, or having the elastically deformable loop itself function as a
cautery wire, with the barrier membrane being perforated at specific
locations to permit electricity or heat flow to the tissue. Alternatively,
a conductive polymer which can be electrically heated from outside the
body can be used to line the mouth portion of the barrier membrane, or the
barrier membrane itself can support the flow of heat or electricity
through its body. Insulation 146 can be provided within the housing, for
protection of the housing.
FIG. 3-7 and FIG. 3-8 demonstrate alternative embodiments of the expandable
barrier of this invention.
FIG. 3-7 shows a shallow barrier member 222 wherein the depth of the
barrier membrane 234 is a fraction of the diameter of the mouth 238. The
connecting means 228 fastens to a circular elastically deformable loop 236
which forms a closed ting. This type of expandable barrier member can
function as an internal surgical drape. The housing 210 is shown.
FIG. 3-8 shows another embodiment of this invention. The barrier member 222
is relatively deep: the depth of the barrier membrane 234 is greater than
the diameter of the mouth 238. The connecting means 228 are wires which
are continuations of the elastically deformable loop 236. The elastically
deformable loop 236 is retained within an enclosure 248 formed of the
barrier membrane 234. The barrier membrane 234 is preferably folded over
itself, and self-adhered to form the enclosure 248. The elastically
deformable loop 236 enters the enclosure through openings 250. Each end of
the elastically deformable loop 236 can independently enter the enclosure
at opening 250, as shown. Alternatively, both ends of the elastically
deformable loop 236 can enter the enclosure through one opening 250, not
shown. The elastically deformable loop 236 slidably engages the loop
enclosure 248: in an especially preferred embodiment, the barrier membrane
forms a closed pouch upon retraction of the elastically deformable loop
within the housing when the barrier member is used to collect a tissue
sample, as shown in FIG. 3-5.
Also shown in FIG. 3-8 is a cautery wire 244 which, when deployed, is
located proximal the mouth 238 of the barrier member 222. An insulating
sheath 252 is located within the axial bore which houses the cautery wire
and projects slightly from the distal end of the housing 210.
While a self-adhered barrier membrane 234 is shown, alternate embodiments
are possible. FIG. 39 presents some of the alternatives in cross-sectional
view, the cross-section being taken through line b--b of FIG. 3-7. The
barrier membrane 234 can be a doubled sheet with the elastically
deformable loop 236 between the two surfaces, as shown in FIG. 3-9A. The
doubled sheet can be self-adhered if desired. The barrier membrane 234 can
include rings 260 formed either of the membrane material or of some other
material as shown in FIG. 3-9B. The barrier membrane 234 can be punctured
by the elastically deformable loop 236, as shown in FIG. 3-9C.
Alternately, the barrier membrane 234 can be affixed to the elastically
deformable loop 236 so that sliding of the membrane material over the
elastically deformable loop is substantially impeded (not shown).
FIGS. 3-10, 3-11 and 3-12 show some alternate top and side views of the
elastically deformable loop in the expanded, "memory" configuration. FIG.
3-10 shows a closed circular loop 336, with a connecting means 328. The
housing 310 is shown. The elastically deformable loop is flat in side
view. FIG. 3-11 shows a circular loop 336, in which the connecting means
328 is a continuation of the loop. The loop is flat in side view, and the
elastic connecting bar is sharply angled. FIG. 3-12 shows an oval loop 336
in top view, in which the connecting means 328 is a continuation of the
elastically deformable loop. The loop is curved in side view, and the
connecting bar is gently angled.
The devices of this invention, including the housing and the barrier
member, can be reusable. Preferably the device is disposable or
semidisposable. The barrier member and the housing are generally
disposable, and the remote actuator means is either reused or discarded.
A possibly advantageous variation of this form of the invention is shown in
FIG. 3-13, which shows an arrangement which can be used to insert a catch
bag 434 through a trocar entry, deploy the bag, and allow the removal of
the insertion device prior to removal of the bag itself. Other devices
have not allowed for dissociation of the bag and insertion device.
The principle feature of this variation is the replacement of the closed
loop of metal in the cuff 448 of the bag by two curved arms 436, joined in
the shaft 410 of the instrument, with their tips meeting at the distal
portion of the cuff. Also in the cuff 448 is a drawstring 490 looping
completely around the cuff, with ends passing through the shaft 410 of the
instrument, and fastened to the actuation handle 448, in a manner which
lets the drawstring move with the arms keeping the drawstring essentially
taut.
Initial insertion of the device is accomplished with the bag 434 disposed
around the straightened arms 436, all situated in the instrument shaft
410.
Separating the ends 491 of the strings 490 from the insertion tool external
to the body will allow the insertion tool to be withdrawn. The arms 436
will slide out of the cuff 448, and the drawstring ends 491 will pass
through the shaft 410. This will leave the bag 434 behind with the
drawstring ends coming out of the trocar. An internal pressure seal may be
affected at the proximal end of the shaft 410 or within the shaft.
FIGS. 3-14 and 3-15 show yet another arrangement which can be used to
deploy a catch bag 460 through a trocar entry.
In this case, as in the embodiment of FIG. 3-13 the closed loop of metal is
replaced by two curved arms 462 which are joined in the shaft of the
instrument. In this case however the arms 462 are connected at their
distal end by a heat-shrink polymeric sleeve 464. This acts both as a
connector for the distal ends of arms 462, and as a hinge, allowing the
arms to fold towards each other. Thus FIG. 3-14 shows the device in its
operating position with the loop extending from the distal end of the
instrument. In this position the arms 462 spring apart from each other
into their unstressed configuration, flexible sleeve 464 allowing this
movement. FIG. 3-15 shows the device when the loop is retracted into the
instrument's shaft e.g. for insertion or withdrawal of the device from the
patient. In this case the arms 462 are folded toward each other about
sleeve 464 which acts as a hinge, to allow the loop easily to be retracted
into the shaft. In this embodiment the arms 462 may comprise a regular
resiliently deformable material e.g. a spring metal, or a material
exhibiting pseudoelastic, especially superelastic behavior, especially a
shape memory alloy.
FIGS. 3-16 to 3-18 illustrate the additional use of a bushing 470 to
prevent accidental withdrawal of a deployed filled barrier member, e.g.
collecting pouch, back into the housing 472 and also to prevent tearing of
the barrier member. FIG. 3-16 illustrates the embodiment before deployment
of the barrier, and FIG. 3-17 illustrates the embodiment after deployment
of the barrier.
Referring to FIG. 3-16, a bushing 470 that is substantially funnel shape,
comprising a hollow tubular portion 474, and a frustoconical shaped flange
portion 482 is positioned on the connecting member or deployment rod 476.
The flange portion 482 is resiliently biased radially outward and the
tubular portion 474 is a push fit on rod 476 but slidably relative thereto
when subjected to sufficient force. On the distal side of the bushing 470
a barrier, comprising a superelastic loop 478 and a barrier member 480, is
secured to the deployment rod 476, as in the previous figures.
Referring now to FIG. 3-17, when the barrier is deployed outside the
housing 472 by extending the deployment rod 476, the bushing 470 is
carried with the rod (because of the push fit tubular portion 474) towards
the distal end of the housing 472 until it projects from the end of the
housing 472. In this position the flange portion 482, which is resiliently
biased, snaps against the distal end of the housing so that complete
withdrawal of the bushing 470 back into the housing is prevented by the
flange 482. Withdrawal of the rod 476 is however possible, the rod sliding
relative to the tubular portion 474 of the bushing 470.
Operation and body sample collection by the deployed barrier member 480 can
then take place as before, and then the elastically deformable loop
retracted back into the housing 472 as illustrated in FIG. 3-18. The bore
of the bushing 470 is however sufficiently small that the barrier membrane
480, which is now filled with body samples, is blocked from re-entry into
the housing. It therefore remains suspended outside the housing 472, which
is desirable for some applications. The funnel shaped ends of the bushing
also act to provide a smooth transition substantially to prevent tearing
of the barrier membrane 480 by the housing 472.
It will be appreciated that bushings with shapes other than that
illustrated in FIGS. 3-16 through 3-18 can be used. The preferred features
to be incorporated in any other shaped bushing are a small diameter bore
to prevent barrier member re-entry, a resilient distal end to snap against
the housing, and a smooth opening to avoid tearing of the barrier
membrane.
FIGS. 3-19 and 3-20 show a modified necked loop design for use in
situations where an elastically deformable loop is to be constrained
within a housing. In these figures, FIGS. 3-19 and 3-20 show the modified
loop in the pre-constrained and the constrained configuration
respectively. The sides 500 of the loop come toward each other, overlap at
part 502 ("the necked portion" which is at the distal end of the loop),
and then divert outwards, curving in the opposite sense to that previously
to join to each other. The result is a smaller loop portion 504 adjacent
to the main loop portion 506, in a roughly figure "8" configuration. The
advantage of this necked configuration is that when the loop is
constrained as shown in FIG. 3-20, substantially all the severe
deformation is absorbed by the small loop portion 504, especially the
overlap point 502. Thus if the loop is deployed again, at least main loop
502 will regain the prestrained configuration, ie the same configuration
as illustrated in FIG. 3-19 which showed the loop before constraining.
FIGS. 3-21 and 3-22 show an alternative design, in pre-constrained and
constrained condition respectively. In this case the sides 508 of the loop
turn outwards at points 510 towards the distal end of the loop before they
meet or overlap. The sides then turn towards each other again to join. The
result is a general nipple shape, with a small bulbous section 512
adjacent the main loop region 514. As before, a necked region is formed,
in this case by the outward diversion of the sides of the loop at points
570. The necked region absorbs substantially all the severe deformation on
constraining as before (FIG. 3-22).
In a fourth form of the present invention, a remotely operated device
comprises an elongate housing, and an elastic surgical screen which can be
constrained within the housing. The surgical screen is deployable from
within the housing to assume an expanded memory shape. In the expanded
shape the surgical screen can have any of several functions. The screen
can act as a duct screen, to collect calculi or calculus fragments, and to
prevent the movement of calculus fragments in an undesired direction. The
screen can act as an emboli screen, to prevent the movement of emboli at
or near an operative site. The screen can act as a surgical tool, to hold
or maintain a mass, such as a tissue mass, in a localized area. Generally,
the screen is removed from the patient in its expanded memory shape,
simultaneously removing calculi or residual calculus fragments, emboli or
emboli fragments, or other internal masses. The surgical screen is
preferably moveable to a third position wherein the surgical screen is
partially or fully retracted, and at least a portion of it is constrained
within the housing.
The surgical screens of this invention are deployed with radial asymmetry
from the mouth of the delivering catheter, and are able to traverse
substantially the entire width of a duct with a screening means. The
elastic screen comprises, for example, one or more loops of elastic
material, which may be partially or completely spanned by a semipermeable
material; a graduated series of a bops; or a tassel. Remote means are
provided to project, retract and/or rotate the screen means relative to
the distal end of the housing.
A method of this invention for removing an internal obstruction comprises
(a) inserting a catheter end beyond an obstruction; (b) deploying a
surgical screen from the catheter end; and (c) retracting the surgical
screen to remove the obstruction.
A further method of this invention comprises (a) inserting a catheter end
beyond an obstruction; (b) deploying a surgical screen from the catheter
end; (c) fragmenting the obstruction; and (d) removing the surgical screen
to remove obstruction fragments.
An alternate method of this invention comprises (a) inserting a catheter
end beyond an obstruction; (b) deploying a surgical screen from the
catheter end; (c) fragmenting the obstruction; (d) retracting the surgical
screen into the catheter; and (e) removing the catheter.
Yet another method of this invention comprises (a) inserting a catheter end
beyond an obstruction; (b) deploying a surgical screen from the catheter
end; (c) fragmenting the obstruction; (d) removing obstruction fragments
from the operative site; (e) retracting the surgical screen into the
catheter; and (f) removing the catheter.
FIG. 4-1A is a side view of an unexpanded screen device within a duct,
placed downstream from a blocking calculus. FIG. 4-1B shows the screen
device, the deployment end of which has been placed upstream from the
blocking calculus. FIG. 4-1C shows a screen device which has been expanded
upstream from a blocking calculus. FIG. 4-1D shows a screen device in
place after calculus fragmentation.
FIG. 4-2 shows various stages of deployment of a tasseled surgical screen.
FIG. 4-3 through FIG. 4-5 show alternate embodiments of the surgical screen
portion of a device of this invention.
The devices of this invention have a variety of potential uses. A surgical
screen of the invention herein can be used to capture an undesired mass
from within a duct, for example, for removing a gallstone from the bile
ducts; for removing a kidney stone from the urinary system; or for
removing an emboli from a blood vessel. Alternatively, the surgical
screens can be used during an operative procedure, such as to contain or
hold a discrete mass for further procedures or for removal. For purposes
of example only, and not as a limitation, reference will be made to
calculi produced by a kidney and removed from a ureter using an endoscopic
device. It is to be understood that this is for simplicity of example
only, and that the apparatus, methods and teachings will be similarly
applicable to a variety of uses.
As used herein, the term "screen" refers to a structure which is screened,
perforated, tasseled, or sieve-like, or which functions to separate larger
particulate matter from smaller particulate matter, or, more preferably,
to separate solid matter from fluids.
As used herein, the term "surgical screen" refers to a screen means which
is comprised of an elastic material, preferably a shape memory alloy, and
more preferably a pseudoelastic shape memory alloy. The surgical screen is
compressible for delivery to the operative site. The "operative site" can
be, for example, a surgical site, a biopsy site, the site of an
angioplasty procedure, the site of a diagnostic procedure, and the like.
Once present at the operative site the surgical screen is deployed from
the housing, expands to its memory shape, and substantially spans the
width of the duct. A tissue "mass" refers to a discrete unit of tissue, a
calculus, an emboius, a prosthetic device, and the like.
The surgical screen preferably demonstrates radial asymmetry: it is not
deployed radially from the housing opening. When deployed from the
catheter, the surgical screen is unconstrained, and expands to traverse
the duct. In general, at least 80% of the width of the duct will be within
the perimeter of the surgical screen. More preferably, the surgical screen
is slightly larger than the diameter of the duct, and gently expands apart
against the walls of the duct when in the expanded configuration. When the
surgical screen is used to localize a tissue mass outside a duct, the mass
is preferably contained at the surface of the surgical screen. Preferably
two or more surgical screen devices of different sizes are available
during a procedure. When needed, the surgeon assesses the size of screen
necessary for tissue protection and/or internal mass collection, and
selects a screen which has an appropriate size, shape and/or filter pore
size.
The surgical screen is one or more wire or a strip of elastic material. The
term "elastic material" is used herein to mean a material that has
spring-like properties, that is, it is capable of being deformed by an
applied stress and then springing back, or recovering, to or toward its
original unstressed shape or configuration when the stress is removed. The
elastic material is preferably highly elastic. The material can be
polymeric or metallic, or a combination of both. The use of metals, such
as shape memory alloys, is preferred. Shape memory alloys that exhibit
pseudoelasticity, in particular superelasticity, are especially preferred.
The elastic materials herein exhibit greater than 1% elastic deformation,
more generally greater than 2% elastic deformation. Preferably, the
elastic materials herein exhibit greater than 3% elastic deformation, more
preferably greater than 4% elastic deformation.
The surgical screen differs from the prior art in several key aspects. The
surgical screen is not radially deployed from the housing, nor is the
housing preferably centered in a duct when the screen is expanded, as has
been the case in the prior art. Prior art stone baskets, for example,
provide a radially deployed basket, into which the stone is snagged.
Removal of the stone is dependent upon the successful engagement of the
calculus within the body of the device, so that the calculus is
substantially enclosed within the basket. The devices require manipulation
of the deployed basket, to ensnare the stone for removal. Stone removal is
directly related to the ability of the operator to snag the stone with the
basket. In contrast, the surgical screen traverses the diameter of a duct,
and the inserted end of the catheter remains near the perimeter of duct.
Using a device of this invention, the stone does not have to be caught
within the screen, but is removed at the surface of the screen as the
catheter and screen are withdrawn from the duct. This provides more
control and requires less manipulation than prior art devices. The devices
of this invention are therefore less likely to damage duct walls during
stone withdrawal than those of the prior art. Devices of this invention
are retractable back into the housing for withdrawal, if desired.
Similar numbers refer to similar function throughout the Figures. The
Figures are drawn for clarity and are not drawn to scale.
FIG. 4-1 shows (1a) the introduction of a surgical screen housing 10, in
this case a catheter, into the occluded duct 15; (1b) placement of the
distal end 17 of the housing beyond the calculus 20a; (1c) deployment of
the surgical screen 25; and (1d) fragments 20b of the calculus 20a. The
calculus fragments 20b can be retracted from the duct with the withdrawal
of the catheter housing 10. In an alternative embodiment (not shown) the
calculus 20a is retracted from the duct without fragmentation.
The surgical screen, when expanded, will have a diameter substantially
similar to the inside diameter of the duct being cleared. For example,
when used within a ureter, the diameter of the surgical screen will be
from about 1 mm to about 1 cm. When used within a bile duct, the diameter
of the surgical screen will be from about 1 mm to about 1 cm. When used
within a blood vessel, the diameter of the surgical screen will be from
about 1 mm to greater than about 5 cm. When used to remove a tissue mass
which is not within a duct, the surgical screen will be from about 1 mm or
smaller to about 8 cm or greater. The preferred diameter of the surgical
screen will vary with the specific application and with the specific
anatomy of the patient. In general, the diameter of a surgical screen will
be from about 1 mm or less to about 5 cm or greater, more generally from
about 2 mm to about 3 cm.
The housing 10 is preferably an elongate sheath, having an axial bore
therethrough. The housing 10 can be flexible or rigid, and the rigidity
can vary by region. Standard catheters and laparoscopic devices well known
to the art are appropriate. The axial bore is sized to receive the
surgical screen 25 in a constrained configuration. The axial bore opens to
the environment at the inserted deployment end 17. Opposite the inserted
deployment end 17 is the actuator end (not shown). The actuator end can
include rings, knobs or ridges, for example, for ease of integration with
a separate actuator means (not shown). Suitable actuator means include
slider mechanisms, pistol grip or thumb actuated mechanisms, scissors
handles, and syringe-plunger mechanisms. These and others are well known
to the art. The specific type of actuator mechanism is generally
determined by the personal preference of the surgeon.
The specific configuration and dimensions of the housing will vary with the
use of the device, the parameters of the surgical screen 25, and whether
access for additional laparoscopic or endoscopic devices is provided. In
general the axial bore, into which the surgical screen is constrained,
will have an internal diameter of from less than about 1 mm to about 2 cm
or greater.
The outer diameter of the housing 10 will vary with the application and the
size of the expandable Screen. The housing in an endoscopic device will
have a diameter of from less than about 0.7 mm to about 4.5 cm or greater.
The length of endoscopic devices will be from less than about 10 cm to
about 3 meters or greater. The housing in a laparoscopic device will have
a diameter of from less than about 3 mm to about 1.5 cm or greater. The
length of laparoscopic devices will be from less than about 5 cm to about
20 cm or greater.
The end of the surgical screen housing possesses sufficient lateral
integrity that it is not significantly deformed by the pressure exerted by
the constrained surgical screen. When an endoscopic device of this
invention functions as a catheter and there is little lateral support in
the main body of the catheter, the inserted end of the catheter may
require reinforcement to provide consistent constraint of the surgical
screen element. For example, the surgical screen of this invention can be
delivered to the operative site using the instrument channel, or working
channel, of standard endoscopic devices. Such standard endoscopic devices
may also include other devices, especially a laser, lithotriptor,
visualization means, or crushing stone basket in separate lumina. In a
device having a rigid housing, such as a laparoscopic device, the inserted
end of the housing can have the same physical attributes as the remainder
of the body of the housing.
As shown in FIG. 4-2, the surgical screen is moveable between a first
position (FIG. 4-2A) wherein the screen is constrained within the housing
and assumes a constrained shape, and a second position (FIGS. 4-2B, 4-2C
and 4-2D) wherein the screen means extends past the distal deployment end
and assumes an expanded memory shape. In the expanded memory shape the
screen means acts as a surgical screen, After use, the surgical screen and
the housing are removed from the patient. If desired, the surgical screen
can be removed in its expanded memory shape, simultaneously removing, for
example, calculi or residual calculus fragments. Alternatively, the
surgical screen is retracted into the housing, assumes a constrained
shape, and is replaced within the axial bore before the constrained
surgical screen and the housing are removed from the patient. This method
can be used when residual calculus fragments, for example, have been
removed by irrigation and/or aspiration.
FIG. 4-2 shows a longitudinal cross sectional view of a tasseled surgical
screen. As FIG. 4-2A shows, the housing 110 maintains the constrained
surgical screen 112 in a compressed configuration. Attached to the
constrained surgical screen 112 is a connecting means 114. The connecting
means 114 can be, for example, a bar, flexible wire, sheath, and the like.
If a guide wire is to be used, the connecting means 114 can include a
lumen for placement of the guide wire. Alternatively, a guide wire can be
introduced using a separate lumen. The connecting means 114 connects the
surgical screen to the remote means (not shown) which project, retract, or
rotate the surgical screen relative to the distal deployment opening.
FIGS. 4-2B, 4-2C and 4-2D show the expanded surgical screen 125 in various
degrees of deployment. By varying the amount of deployment, and thus the
diameter of the surgical screen, d, the operator can maximize the
screening effects of the surgical screen while minimizing potential damage
to the duct wall due to surgical screen expansion, or due to the
withdrawal of the expanded screen from the body.
FIG. 4-3 shows one embodiment of a surgical screen 225 of this invention.
Three elastic strips or wires form concentric loops in their expanded
configurations. These strips or wires form a surgical screen 225 suitable
for removal of entire calculi, or of calculus fragments. It will be
obvious to one skilled in the ad that while three loops which are curved
along their length are pictured, other configurations are also appropriate
for use with this invention. One, two, four, or more loops can be used.
The loops can be fairly regular (as shown), or they can be eccentric,
scalloped, rounded, oval or irregularly shaped. The degree of longitudinal
curvature, and curvature across the width of the screen, can be varied to
suit the desired application. The loops can be spaced relatively widely,
especially where an unfragmented calculus is to be removed, or they can be
spaced fairly closely together, especially where a calculus is to be
fragmented and/or calculus fragments are to be removed. A perforated sheet
can be suspended across a loop of a multiloop surgical screen, similar to
the configuration shown in FIG. 4-5. Alternatively, a perforated sheet can
be suspended between any two loops of a multiloop surgical screen (not
shown).
FIG. 4--4 shows a side view of a tasseled surgical screen 225 of this
invention. Enlargements show various end treatments for the tassels.
Pictured are (a) an elastic wire which terminates in a self-closing loop;
(b) an elastic wire that terminates in a blunted or truncated end; (c) an
elastic wire that terminates in a knob of added material, such as a
plastic; and (d) an elastic wire that terminates in a knob formed of the
elastic material itself. Each individual strand which makes up a tassel
filter can be substantially straight along its length, or it can be
curved, wavy, or undulating in two or three dimensions. The strands can be
substantially similar in configuration, or they can be different.
FIG. 4-5 shows a surgical screen which includes an elastic loop 236, an
elastically deformable ring or loop of elastic material, which is spanned
by a barrier material 234. The elastic loop 236 is preferably
pseudoelastic, and more preferably a shape memory alloy. As shown, a
connector 228 can be used to orient the surgical screen sharply across the
duct. The pictured connector 228 is an extension of the elastic loop 236.
Alternatively, the connector 228 can integrate with, but be separate from
the elastic loop 236.
The diameter of the elastic loop 236 will vary with the diameter of duct
for which it is intended, as discussed above. The depth of arc described
by the barrier material 234 when suspended from the memory loop is from
less than about 1 mm to about 1 cm or greater. The surgical screen can
provide a sack-like structure which substantially encloses a calculus. The
calculus can then be removed without fragmentation, or it can be
fragmented. If the calculus is fragmented, the pieces can be removed
within the surgical screen, they can be aspirated or irrigated from the
face of the surgical screen, or the surgical screen can be retracted and
the fragments can be washed from the site by normal duct fluid flow.
The barrier material is a flexible and biocompatible material. When
constrained, the barrier material 234 is collapsed and furled around the
constrained elastic loop 236. The barrier material is sufficiently thin
that it can be folded, furled, or gathered, together with the elastic loop
236, to fit within the housing. The composition of the barrier material
will reflect the specific use of the surgical screen. In one embodiment
the barrier material is substantially permeable to fluids. In such an
embodiment, the barrier material is a web, net or grid, perforated sheet,
and the like, and is substantially permeable to body fluids and other
liquids, such as normal saline solution or gases, which might be present
during surgical procedures. Suitable materials include nylon or Dacron
netting or screen, or a grid of elastic material.
The surgical screen is compressed and loaded within the housing. In this
constrained configuration, the screen device can be sterilized, packaged
and stored for later use. The screen device (i.e., surgical screen and
housing) is preferably a disposable device.
In one preferred embodiment, a device of this invention comprises (a) a
housing having a distal deployment opening; (b) a surgical screen which is
constrainable within the housing, the surgical screen comprising an
elastic material; and (c) remote means to project, retract and/or rotate
the surgical screen relative to the distal deployment opening; the
surgical screen being moveable between a first position wherein the
surgical screen is constrained within the housing, and a second position
wherein the surgical screen is extended past the distal deployment end and
assumes an expanded shape.
A device of this invention can be used in a variety of procedures, such as
the capture an undesired mass from within a duct. For example, a device of
this invention can be used to remove a gallstone from the bile ducts; to
remove a kidney stone from the urinary system; or to remove an embolus
from a blood vessel. A surgical screen of this invention can be used
during an operative or surgical procedure, to contain or hold a discrete
tissue body for further procedures or for removal. For purposes of example
only, and not as a limitation, reference will be made to methods for
removal of a calculus from a ureter, wherein the device housing is a
catheter. It is to be understood that this is for simplicity of example
only, and that the apparatus, methods and teachings will be similarly
applicable a variety of such uses.
In one method, the deployment end of a housing containing a surgical screen
is partially inserted into a human or animal patient. A guide wire may or
may not be used for placement of the device. When a guide wire is used, it
is introduced into the ureter and placed appropriately, e.g., beyond an
obstruction. A catheter is slipped over the guide wire. The guide wire is
then removed, and the surgical screen is extended beyond the deployment
end of the catheter. The guide wire preferably passes through a separate
lumen in the catheter. Alternatively, the guide wire can pass through the
catheter lumen which houses the surgical screen, in which case the
connecting means can be tubular and provide an internal bore to accept the
guide wire, Alternatively, the guide wire can pass through the axial bore
of the housing adjacent the connecting means, or the guide wire can be
introduced through a bore or slot within the connecting means. The
surgical screen can be radiopaque for ease of placement at the operative
site.
A method for removing an internal obstruction comprises (a) inserting an
end of an elongate housing, such as a catheter end, beyond a mass, such as
a calculus; (b) deploying a surgical screen from the housing end; and (c)
retracting the housing and surgical screen to remove the mass.
Alternately, the calculus can be fragmented before removal. Calculus
fragmentation can be by, for example, lithotripsy (ultrasound), mechanical
fragmentation, or laser fragmentation. This method comprises (a) inserting
a catheter end beyond a mass; (b) deploying a surgical screen from the
catheter end; (c) fragmenting the mass; and (d) retracting the catheter
and surgical screen to remove mass fragments.
Yet another method of this invention comprises (a) inserting a catheter end
beyond a mass; (b) deploying a surgical screen from the catheter end; (c)
fragmenting the mass; (d) removing mass fragments from the operative site;
(e) retracting the surgical screen into the catheter; and (f) removing the
catheter. The use of this method prevents calculus fragments from
migrating from the fragmentation site where they cannot be retrieved and
can act as nucleation sites for further obstructions. Fragments of the
obstructing mass which remain can be removed, for example, by flushing the
operative site with normal saline or other liquids, by aspiration of the
fragments, by mechanical means, or by a combination of means.
As a separate embodiment of this invention, it has been discovered that
stone baskets of the prior art can be advantageously made of a shape
memory alloy, preferably a pseudoelastic shape memory alloy, and more
preferably a superelastic shape memory alloy. The attributes of, and
processes for obtaining, such shape memory alloys have been discussed
above.
Stone baskets use a trap, or cage, effect. They facilitate passage of the
obstruction (e.g., a calculus or other mass) inside the basket, but then
prevent escape of the obstruction when it is in place in the basket. The
basket and obstruction are then withdrawn. Prior art stone baskets include
baskets of helically deployed wires (U.S. Pat. No. 4,347,846, to Dormia),
baskets of flat spring strips (U.S. Pat. No. 4,590,938 to Segura et al.),
baskets which facilitate the insertion of a prosthesis (U.S. Pat. No.
4,592,341 to Omagari et al.), baskets which are used to capture and then
crush the calculus (U.S. Pat. Nos. 4,691,705 and 4,741,335 to Okada, and
4,768,505 to Okada et al.).
Stone baskets generally are classed as medical retriever devices. They are
adapted for delivery and use through a catheter, or through the working
channel of an endoscope. Stone baskets generally comprise a narrow,
elongated sheath; a basket of relatively large diameter extendible from
the distal end of the sheath and collapsible when withdrawn into the
sheath; and a remote means to project, retract, and/or rotate the basket
relative to the distal end of the sheath. The basket is defined by a
multiplicity of spaced apart, outwardly bowed spring arms or wires which
extend generally axially from the sheath, and are joined at each of the
distal and proximal ends of the basket.
The use of shape memory alloys which exhibit pseudoelasticity in the stone
baskets of the prior art allow the use of thinner arms (wires or strips,
as the case may be) in the makeup of a basket having a desired expanded
diameter, or permit a much greater deformation of the basket upon
deployment. This permits the use of catheters or working channels having a
significantly decreased diameter than those of the prior art. Introduction
of a thinner shape memory alloy stone basket catheter beyond a calculus is
easier than introducing the stone basket catheters of the prior art. The
increased diameter and/or thinner wires produce a stone basket which is
easier to use than those of the prior art. The thinner wires and/or larger
diameter provide more unimpeded area into which the blocking calculus can
be captured for removal.
In a fifth form of the present invention, a remotely operated device of
this invention comprises an elongate housing, and a retractor of a shape
memory alloy. Remote means are provided to project, retract and/or rotate
the retractor means relative to the distal end of the housing. The
retractor preferably comprises one or more loops of a shape memory
material. The retractor is preliminarily constrained within a housing,
such as a laparoscope or an endoscope. It is deployed from within the
housing at an operative site. The retractor is generally used to
manipulate organs or other tissues. The retractor can be replaced within
the housing. The housing is then withdrawn from the patient.
The shape memory retractor means is a strip or wire of a shape memory
material which forms one or more loop in the expanded configuration. All
or part of the retractor can be spanned by a semipermeable or permeable
membrane.
FIG. 5-1 is a cross-sectional view of a constrained retractor device. FIGS.
5-2 through 5-6 show alternate top views of expanded (unconstrained)
retractor devices. FIGS. 5-7 through 5-11 show alternate side views of
expanded retractor devices. FIGS. -12 and 5-13 show alternate end views of
expanded retractor devices. FIGS. 5-14 and 5-15 show alternate cross
sectional views of constrained retractor devices, the cross section taken
along line a--a of FIG. 5-1.
A remotely operated device of this invention comprises an elongate housing
having a distal end and a proxima1 end; a retractor of a shape memory
alloy; and remote means to project, retract and, optionally, to rotate the
retractor means relative to the distal end of the housing. The retractor
comprises one or more loops of a shape memory material. A loop can be
substantially round, oval, or shaped like a teardrop, for example, or it
can be eccentric in its shape. When two or more loops are present, they
can be of similar shape, or they can be dissimilar in shape. Two or more
fingers or lobes can be present. One or more loop can be partially or
completely spanned by a membrane. The proximal ends of the retractor loop
can integrate with, or function as, the remote means to project, retract
and rotate the retractor means relative to the distal end of the housing.
The retractor is preliminarily constrained within the housing. The
retractor is deployed at an operative site, where the retractor is used,
for example, to manipulate organs or other tissues. The retractor can be
moved back to the preliminary position, so that the retractor is again
constrained within the housing. The device can then be repositioned and
the retractor redeployed at an alternate site, or the housing can be
withdrawn from the patient.
The operative site can be, for example, a surgical site, biopsy site, the
site of diagnostic procedures, and the like. For purposes of example only,
and not as a limitation, reference will be made to a housing which is a
catheter. It is to be understood that this is for simplicity of example
only, and that the apparatus, methods and teachings will be similarly
applicable to devices in which the housing is, for example, a laparoscopic
or alternate endoscopic device.
As used herein, the term "retractor" refers to a looped retractor means
which is comprised of a shape memory alloy. The retractor is preferably a
pseudoelastic shape memory alloy, and most preferably a superelastic shape
memory alloy. The shape memory alloy can have a biocompatible coating, if
desired.
The retractor differs from the prior art in several key aspects. The
elastically compressible retractor material makes use of the property of
shape memory to achieve its desired effect. Materials which are deformable
and which return to a predetermined shape demonstrate shape memory. Spring
steel and plastic materials, for example, can demonstrate shape memory.
Preferably, the compressible retractor material is a shape memory alloy
(SMA) which demonstrates pseudoelasticity when deformed under an applied
stress. Articles made of a pseudoelastic shape memory alloy can be
deformed from an original undeformed configuration to a second deformed
configuration. Such articles revert to the undeformed configuration under
specified conditions, and are said to have "shape memory."
The use of an SMA which exhibits pseudoelasticity has the advantage that
the amount of elastic deformation that is available is large compared with
that available from many other materials. The large amount of elastic
deformation of the elements allows the device to be used to form
retractors of relatively large dimension and relatively eccentric shape,
while simultaneously ensuring that the device has a small transverse
dimension when the retractor elements are constrained within a housing,
allowing the device to pass through small passages or surgical entry
sites.
FIG. 5-1 shows a cross-sectional view of the distal end of a retractor
device of this invention. The retractor 8 is constrained within the
housing 10. The distal (inserted) deployment end 12 is shown. Remote means
to project and retract, and optionally to rotate, the retractor is located
at the proximal end of the device (not shown), and is in the direction of
the arrow. The housing 10 is preferably an elongate sheath, having an
axial bore 14 therethrough. Standard catheters, endoscopic and
laparoscopic devices well known to the art are appropriate. The axial bore
14 is sized to receive the retractor 8 in a constrained configuration. The
axial bore 14 opens to the environment at the deployment end 12.
The specific configuration and dimensions of the housing will vary with the
use of the device, the parameters of the operative site, the size of the
retractor, the mass of tissue or the prosthetic device which is to be
manipulated, and whether access for additional laparoscopic or endoscopic
devices is provided within a retractor device. In general the axial bore
14, into which the retractor is constrained, will have an internal
diameter of from less than about 1 mm to about 2 cm or greater. The outer
diameter of the housing 10 will vary with the application, the diameter of
the axial bore, and whether access for additional or alternate instruments
is provided within the housing. For example, the housing in an endoscopic
device will have a diameter of from less than about 0.7 mm to about 4.5 cm
or greater. The length of endoscopic devices will be from less than about
10 cm to about 3 meters or greater. The housing in a laparoscopic device
will have a diameter of from less than about 3 mm to about 1.5 cm or
greater. The length of laparoscopic devices will be from less than about 5
cm to about 30 cm or greater.
The end of the retractor device possesses sufficient lateral integrity that
it is not significantly deformed by the pressure exerted by the
constrained retractor. The housing 10 may be rigid or flexible, and its
rigidity can vary along its length. When an endoscopic device of this
invention functions as a catheter, and there is little lateral support in
the main body of the catheter, the inserted end of the catheter may
require reinforcement to provide consistent transverse compression of the
retractor element. A retractor of this invention can be delivered to the
operative site using the instrument channel, or working channel, of a
standard laparoscopic or endoscopic device. Such a standard device may
also include other devices, especially a cautery device, laser,
lithotriptor, visualization means, scalpel means, and the like, in one or
more separate lumina.
FIG. 5-2 shows a top view of an expanded retractor of this invention. The
retractor 108 has three loops 116 which fan out from the housing 110 upon
deployment. One or more of the loops can be spanned by a membrane (see
FIG. 5-4). While three loops are shown, it will be apparent to one skilled
in the art that one, two, four, or more loops can be provided to form the
retractor. While the loops 116 pictured are substantially drop-shaped,
other configurations are easily imagined. The loop or loops 116 can be,
for example, round, oval, triangular, square, rectangular, irregularly
shaped, and the like. When two or more loops are present the loops can be
substantially similar in shape, or they can be dissimilar in shape.
The loops 116 can overlap, or they can be be substantially independent from
one another. In such a case a deforming pressure placed upon one loop
perpendicular to the general plane of the loop will deform that loop, but
will not affect the other loops. In a preferred embodiment, the loops 116
are interconnected and/or overlapping, and a deforming pressure placed
upon one loop perpendicular to the general plane of the loop will be
transmitted to the other loops. All loops thus act together, providing
strength across the width of the retractor. The loops can be coated with a
biocompatible material. The coated or uncoated loops can have a surface
that prevents slippage of the retracted tissue; For example, the
biocompatible coating can provide a roughened or non-slippery texture to
the loops. Alternatively, the loops can have gentle ridges or serrations
upon all or part of the exposed surface.
FIG. 5-3 shows a top view of an expanded retractor of this invention. This
preferred retractor 108 has three lobes, or finger means 118 which fan out
from the housing 110 upon deployment. One or more of the finger means can
be spanned by a membrane (see FIG. 5-4). Alternatively, one or more of the
spaces between fingers can be spanned by a membrane (see FIG. 5--5).
FIG. 5-4 shows a top view of another expanded retractor of this invention.
This retractor 108 has one loop means 116 which expands upon deployment
from the housing 110. As shown, the loop is spanned by a permeable,
semipermeable or substantially impermeable membrane 120. The membrane 120
is preferably made of a flexible and impermeable biocompatible material.
The membrane is sufficiently thin that it can be folded or gathered,
together with the elastically deformable retractor means 108, to fit
within the housing 110. Suitable membrane materials include sheets of
polyethylene, polyvinyl chloride, urethane, silicone rubber, and the like.
In an alternative embodiment, the membrane 120 is substantially impermeable
to tissue, but is generally permeable to body fluids and other liquids
which might be present during surgical procedures. In this embodiment, the
membrane 120 can be a grid of shape memory material, a net, a web, and the
like. Suitable materials include perforated, webbed or netted
polyethylene, polyvinyl chloride, urethane, silicone rubber, and the like.
FIG. 5--5 shows a top view of yet another expanded retractor of this
invention. This retractor 108 has two lobes, or finger means 118 which fan
out upon deployment from the housing 110. The space between the fingers is
spanned by a membrane 120.
FIG. 5-6 shows a top view of an alternate expanded retractor of this
invention. Emerging from the housing 110 is a retractor 108 which has two
loops 116. As shown, a smaller loop 116a is nested within a larger loop
116b. In the pictured embodiment, the smaller loop 116a is spanned by a
membrane 120. It will be apparent to one skilled in the art that any
number of such loops, in various configurations, whether or not spanned by
a membrane 120 either across or between loops, can be provided to form the
retractor.
FIGS. 5-7 through 5-11 show side views of a deployed retractor of this
invention.
FIG. 5-7 shows a side view of a deployed retractor of this invention. The
amount of elastic curvature of the retractor 208 is greatest at the base
of the retractor, where the retractor emerges from the housing 210.
FIG. 5-8 shows an alternate side view of a deployed retractor of this
invention. The amount of elastic curvature of the retractor 208 is fairly
consistent across the length of the retractor 208.
FIG. 5-9 shows yet another side view of a deployed retractor of this
invention. The retractor 208 has the smallest radius of curvature at its
distal end.
In FIG. 5-10, the retractor 208 is substantially straight upon deployment
from the housing 210.
FIG. 5-11 shows a retractor 208 which is gently curved.
FIGS. 5-12 and 5-13 show alternate end views of an expanded (unconstrained)
retractor, such as shown by arrow E in FIG. 5-10. In end view, the
expanded retractor can be flat. However, using the shape memory material
retractors of this invention, other configurations are possible. FIG. 5-12
shows a retractor which is gently curved across its width. FIG. 5-13 shows
a retractor 308 which is asymmetrical: it is flattened on one side, and
curved or hooked on the other side. These configurations find particular
application when the mass to be gently manipulated by the retractor is
substantially parallel to the length of the retractor device or retractor
housing. As used herein, the term "mass" refers to a tissue mass, or to a
prosthetic device. Other configurations in addition to the flattened
silhouette, and the curved configurations shown in FIGS. 5-12 and 5-13,
will be readily apparent to one skilled in the art. For example, the
retractor may be sharply angled, or it may be twisted along its length.
The retractor may also have curvature in two or more directions in any of
the planes described, such that the retractor may have a zig-zag or
undulating appearance.
The various embodiments shown in FIGS. 514 2 through 5-13 can be combined
as desired. A retractor of this invention can comprise, for example, the
three-fingered shape of FIG. 5-3, curved along its length as shown in FIG.
5-8, and curved along its width as shown in FIG. 5-12. Such a retractor is
generally cup-shaped.
FIGS. 5-14 and 5-15 show alternate cross-sectional views of a constrained
retractor, taken at line a--a of FIG. 5-1. FIG. 5-14 shows a retractor
made of wires 408 having a circular cross section, the retractor being
constrained within the housing 410. FIG. 5-15 shows a retractor of strips
408 having an oval cross section. It will be clear to one skilled in the
art that many other wire or strip cross-sections are equally appropriate
for use in the retractors of this invention. For example, the retractor
can be made of a strip member which is squared, rectangular, triangular,
and the like. A cross-section such as the oval shape of FIG. 5-15 is
generally preferred for the retractors of this invention. Such a
cross-section provides strength upon the application of force which is
perpendicular to the general plane in which the retractor is elastically
deployed, but provides minimized dimensions and resistance upon constraint
of the retractor within the housing 410.
In one preferred embodiment, a device of this invention comprises (a) a
housing having an axial bore with a distal deployment opening; (b) a
retractor which comprises a loop shape, the retractor being constrainable
within said axial bore, and the retractor comprising a shape memory alloy;
and (c) remote means to project and retract, and, optionally, to rotate,
said retractor relative to the distal deployment opening. The retractor is
moveable between a first position wherein the retractor is housed within
the axial bore and assumes a constrained shape, and a second position
wherein the retractor is extended past the distal deployment end and
assumes an expanded memory shape.
The retractor is compressed and loaded within the housing. In this
constrained configuration, the retractor device can be sterilized,
packaged and stored for later use. The retractor device (i.e., retractor,
housing, and deployment means) is preferably a disposable device. When
needed, the surgeon visually assesses the size of retractor necessary for
tissue manipulation, and selects a retractor which has an appropriate
diameter, curvature and/or membrane.
In use, the device is partially inserted into a human or animal patient and
used to manipulate organs or other tissues at an operative site. A guide
wire may or may not be used for placement of the device. When a guide wire
is used, it is introduced into the operative site and placed
appropriately. A catheter containing a retractor is slipped over the guide
wire. The guide wire is then removed, and the retractor is extended beyond
the deployment end of the catheter. The guide wire preferably passes
through a separate lumen in the catheter. Alternatively, the guide wire
can pass through the catheter lumen which houses the retractor. The
retractor can be radiopaque for ease of identification and use at the
operative site.
A sixth form of the present invention provides a sheath-protected blade
wherein the sheath is substantially straight. When it is constrained
within the sheath, the blade is substantially linear. Upon deployment from
the sheath, the blade is unconstrained, and assumes a configuration which
is elastically deflected away from the longitudinal axis of the sheath.
The blade is an elastically deformable material, preferably a
pseudoelastic material, and more preferably a shape memory alloy.
One or more exposed edge of the elastic blade can provide a cutting edge.
Exposed surfaces which are blunted can provide a means for manipulation of
tissues or artificial devices.
FIG. 6-1 is an external view of a device of this invention.
FIGS. 6-2 and 6-3 are alternate cross-sectional views of a sheath of this
invention, the cross sections being taken vertically along the
longitudinal axis of FIG. 6-1.
FIG. 6-4 is an alternate cross-sectional view of a sheath of this
invention, the cross section being taken vertically along the longitudinal
axis.
FIG. 6-5 is a cross-sectional view of the device of FIG. 6-1 taken across
the longitudinal axis, along line b--b of Rg. 6-1. FIG. 6--6 is a
cross-sectional view of the device of FIG. 6-1 taken across the
longitudinal axis, along line c--c of FIG. 6-1.
FIG. 6-7 is a cross-sectional view of a cutting edge of a cutting blade of
this invention.
FIGS. 6-8 through FIG. 6-12 are alternate side views of the device of FIG.
6-1 when the cutting blade is deployed.
FIG. 6-13 through FIG. 6-20 are alternate top views of typical elastic
blades of this invention.
A remotely operated device of this invention comprises an elongate housing,
and an elongate blade which can be linearly constrained within the
housing. The elastic blade is deployable from within the housing, and
assumes a curved unconstrained shape upon deployment. Remote means are
provided to project and retract, and optionally to rotate, the elastic
blade relative to the distal end of the housing. Alternatively, remote
means are provided to project and retract the sheath relative to the
elastic blade.
The sheathed blade device of this invention differs from the prior art in
several key aspects. The sheath is substantially straight along its
length. When constrained within the sheath, the elastic blade is also
substantially straight along its length. When deployed from the sheath the
elastic blade assumes, as much as possible, its curved unconstrained
shape.
The blades of this invention are curved (e.g., curled or twisted) along
their length to a greater or lesser degree. The degree of curvature can be
consistent along the length of the blade, or the curvature can vary in
degree and/or in direction. A cutting surface can be provided at any
desired exposed edge of the blade. When the unconstrained shape of the
elastic blade is generally semicircular (such as shown in FIG. 6-8) a
cutting surface can be provided along the sides of the blade (such as
shown in FIGS. 6-13, 6-14, and 6-19). Alternatively, a cutting surface can
be provided at the tip of the blade (such as shown in FIGS. 6-15, 6-16,
and 6-17) to provide a scalpel which has a cutting surface directed
180.degree. from the opening of the sheath. Varying the amount of
deployment of the blade varies the cutting angle, so that a blade can be
provided in which the cutting surface is angled from 0.degree. to
180.degree. or greater from the axis of the sheath.
The elastic nature of the blade allows for a complete retraction of the
blade into the sheath for a complete protective enclosing of the blade,
protecting both the blade and the body tissue during both the insertion
and removal of the instrument. The sheath not only protects the blade but
also guides and directs the blade whereby the extension of the blade from
the sheath can comprise a cutting movement of the blade, rather than
merely a means for exposing the blade for subsequent manipulation. The
user, upon selection of the appropriate elastic blade (i.e., a blade
having a desired curvature and position of cutting edge), orients the
sheath, and then extends the blade. The blade is extended either by moving
the blade outward from the sheath, or retracting the sheath relative to
the blade.
Similar numbers refer to similar function throughout the Figures. The
Figures are drawn for clarity and are not drawn to scale.
FIG. 6-1 is an external view of a device of this invention. The housing 10
is an elongate member, having an axial bore therethrough. The housing has
a distal end 12, which acts as a sheath for the elastic blade, and a
proximal end 14, which provides integration with a means to project and
retract the elastic blade relative to the distal end of the housing 10.
Between the distal end 12 and the proximal end 14 is the housing body 16.
The housing preferably also includes a remote means 18, the actuation of
which causes the elastic blade to be deployed from the housing, or the
housing to be retracted from the blade. The remote means 18 can be
actuated by any manual or motorized means (not shown). In one embodiment,
as pictured, two finger rings 20 are part of the proximal end 14. An
additional thumb ring 22 is part of the remote means 18. When the thumb
ring 22 is depressed, the elastic blade (not shown) is deployed from the
housing at the distal end 12. The pictured rings are for ease of handling.
Alternatively, knobs or ridges, for example, can be provided for ease of
integration with a separate actuator means (not shown). Separate actuator
means include slider mechanisms, pistol grip or thumb actuated mechanisms,
scissors handles, and pistol-grip mechanisms. These and others are well
known to the art. The specific type of actuator mechanism is generally
determined by the personal preference of the surgeon. The orientation of
the blade relative to the actuator mechanism can be configured to suit the
specific application or the preference of the surgeon.
The distal end 12 of the housing acts as a sheath which constrains the
elastic blade in a substantially linear configuration. It possesses
sufficient lateral integrity that it is not significantly deformed by the
pressure exerted by the constrained elastic blade. When an endoscopic
device of this invention is a catheter and there is little lateral support
in the housing body 16, the distal end 12 of the catheter may require
reinforcement to provide consistent constraint of the elastic blade (not
shown). In a device having a rigid housing, such as a laparoscopic device,
the distal end 12 of the housing can have the same physical attributes as
the remainder of the housing. Standard endoscopic and laparoscopic devices
well known to the art are appropriate for use with the elastic blades of
this invention.
The housing body 16 of a device which is used in laparoscopy must have
sufficient structural integrity that it is easily inserted through a
surgical opening into the body of the patient without undue deformation.
Materials with sufficient structural rigidity include stainless steel and
rigid polymeric materials such as plastics. The material of the proximal
end of the housing 14, the material of the housing body 16, and the
material of the distal end 12, can be the same, or can have different
physical properties. For example, the housing body 16 used in endoscopic
surgery will generally be flexible, to allow insertion through naturally
occurring orifices, ducts, and/or passages, or to allow insertion through
the working channel of an endoscope. Suitable polymeric material includes
polytetrafluoroethylene, polyurethane, polyethylene, Teflon, and the like.
The material of such a flexible housing may be reinforced at the distal
end 12 with fibers, rings, or longitudinal ribs, for example, to enable it
to withstand the forces exerted on it by the elastic blade while it is
constrained within, and deformed by, the housing.
The specific configuration and dimensions of the housing 10 will vary with
the use of the device, the parameters of the elastic blade, and whether
access for additional laparoscopic or endoscopic devices is provided. The
housing 10 can be substantially uniform along its length, as shown in FIG.
6-1, or it can vary in diameter or shape, as shown in FIG. 6-4.
Preferably, the housing 10 has a circular cross-section. A circular
cross-section permits delivery of an elastic blade of this invention
through a standard laparoscopic trocar, or through the instrument channel
of a standard endoscope. However, other cross-sections may be preferable,
for example, to adapt an endoscopic device to the orifice through which it
will enter the body.
In general, the housing in an endoscopic device will have an outside
diameter of from less than about 0.7 mm to about 4.5 cm or greater. The
length of endoscopic devices will be from less than about 10 cm to about 3
meters or greater. The housing in a laparoscopic device will have an
outside diameter of from less than about 0.3 mm to about 1.5 cm or
greater. The length of laparoscopic devices will be from less than about 5
cm to about 30 cm or greater.
FIGS. 6-2 and 6-3 are alternate cross-sectional views of a device of this
invention, the cross section being taken vertically along the longitudinal
axis of the distal end 12 of FIG. 6-1.
FIG. 6-2 shows the distal end 112 of a housing 110 which is made as one
unit. An axial bore 130 runs axially through the housing. At the proximal
end 132 of the axial bore 130, the axial bore can have any convenient size
and shape. In general the axial bore will have an internal diameter of
from less than about 0.5 mm to about 2 cm or greater. At the distal end,
the axial bore becomes flattened, and forms the sheath bore 134 for the
constrained elastic blade 136. The sheath bore 134 is sized to slidably
accept the constrained elastic blade 136, and to constrain the elastic
blade 136 in a substantially linear configuration. When the elastic blade
136 is fully housed within the sheath bore 134, the sheath bore 134
contains at least those portions of the elastic blade 136 which have
cutting edges. Preferably the cutting edges of the elastic blade 136 do
not touch or rub against the sheath bore 134 when stored, or upon
deployment or retraction, as such contact can dull the cutting edges.
In general the proximal end 132 of the axial bore 130 will be circular and
relatively large, to facilitate the loading of the connecting means 138
and the elastic blade 136 within the sheath. A circular conformation is
for general ease of manufacture and handling, and alternate conformations
can be used, as desired. The proximal end 132 of the axial bore 130 houses
the connecting means 138. The connecting means 138 can be, for example,
soldered or otherwise affixed to the elastic blade. Alternatively, it can
be a continuation of the elastic material used to form the elastic blade
136.
FIG. 6-3 shows the distal end 112 of a housing 110 which is made as two
units. One unit is a tube 140 through which extends an axial bore 130. A
bushing 142 is fitted within the tube, for example by press fit or by
thread. The bushing 142 provides the sheath bore 134 for the constrained
elastic blade 136. The bushing 142 can be made of any suitable material,
polymeric and/or metallic. It may be desirable to pass an electric current
through the elastic blade 136, so that the elastic blade 136 acts as an
electrocautery device. In such an embodiment the bushing can be a
non-conducting polymer, and it can act to keep the elastic blade 136
electrically insulated from the housing 110. The elastic blade 136 is held
for reciprocal motion by the connecting means 138.
FIG. 6-4 is an alternate cross-sectional view of the distal end 112 of a
housing 110 of this invention, the cross section being taken vertically
along the longitudinal axis. In this embodiment the housing 110 is a metal
or plastic tube which has been flattened at one end. The flattened end
provides the sheath bore 134 in which the elastic blade is slidably
constrained. The elastic blade 136 is held for reciprocal motion by the
connecting means 138.
If the housing 110 is a tubular structure having a flattened end, as shown
in FIG. 6-4, it may be desirable to provide a covering of any suitable
material (not shown). The covering provides a uniform outer dimension for
the device. A covering which provides a substantially uniform circular
cross-section is advantageous if the blade device is to be introduced into
the body through a standard laparoscopic trocar, or through the instrument
channel of a standard endoscope. The covering acts to minimize the escape
of fluids (either liquid or gas) from the body. The covering can be made
of a polymeric material such as polyurethane, polyethylene, and the like.
FIG. 6-5 is a cross-sectional view of the device of FIG. 6-2 taken across
the longitudinal axis at line b--b. The housing 210 surrounds the axial
bore 230. Within the axial bore is the connecting means 238. The
connecting means 238 can have any suitable cross-sectional shape. In the
shown embodiment the connecting means 238 spans axial bore 230 to minimize
lateral motion as the sheath and elastic blade (not shown) are moved
longitudinally relative to each other. If an electric current is passed
through the connecting means 238 and the elastic blade, so that the
elastic blade acts as an electrocautery device, it may be desirable to
include a layer of a non-conducting material (not shown) around connecting
means 238 to insulate the connecting means 238 from the housing 210.
FIG. 6--6 is a cross-sectional view of the device of FIG. 6-2 taken across
the longitudinal axis at line c--c. The housing 210 surrounds the sheath
bore 234. Within the sheath bore is the elastic blade 236.
One or more edges of the elastic blade 236 can remain dull, and can aid the
non-cutting manipulation of tissues or artificial devices during surgery.
For instance, the blade can have no cutting edges. This minimizes the
amount of trauma to surrounding tissues upon manipulation of the blade.
More generally, the elastic blade 236 has one or more sharpened edges 240.
The sheath bore 234 is substantially flattened, and holds the elastic
blade 236 so that the elastic blade 236 is constrained linearly. In a
preferred embodiment, the sheath bore 234 is slightly enlarged in the
region of the sharpened edges 240. This acts to protect the sharpened
blade from wear as it is deployed from, and withdrawn into, the housing.
Alternatively, the sheath bore 234 closely mimics the outer shape of the
elastic blade 236. Other embodiments are also possible, such as a sheath
bore 234 which is substantially rectangular or eccentric, and such
embodiments will be readily apparent to one skilled in the art.
FIG. 6-7 is a cross-sectional view of a cutting edge of a cutting blade of
this invention. A cutting edge can be provided at any edge of the elastic
blade. In a preferred embodiment, the edge of the elastic material is
beveled, and provides a cutting blade. FIG. 6-7 shows a cutting edge which
is beveled on both sides. The bevel or bevels can be at any appropriate
angle from the plane of the blade. When two bevels are present, they can
have the same angle of bevel, or different angles of bevel. In FIG. 6-7,
the bevels are .beta. and .phi. degrees from the plane of the blade.
Alternatively, only one bevel may be present (not shown). The honing of an
edge to form a cutting blade is well known in the art. If desired, the
cutting blade can be serrated. The cutting edge is preferably derived from
the beveled elastic material itself. However, it may be desirable or
necessary to provide a honed blade edge to the elastic material. This
additional blade can be added mechanically, as shown in FIG. 6-12.
Alternatively, two or more elastic materials can be used to form the
blade. For example, a non-cutting elastic blade can be combined with an
elastic alloy blade having a cutting edge.
FIGS. 6-8 through 6-11 are side views of the device of FIG. 6-1 when the
elastic blade is deployed. A cutting surface can be provided at any
desired exposed edge of the blade.
FIG. 6-8 shows an elastic blade 336 which is substantially semicircular
upon deployment from the housing 310. The degree of curvature can be
substantially consistent along the length of the blade, as shown, or the
curvature can vary, i.e., the elastic blade can have a uniform or
non-uniform radius of curvature.
FIG. 6-9 shows an elastic blade 336 which describes an S-shaped curve upon
deployment from the housing 310.
FIG. 6-10 shows an elastic blade 336 which is twisted along its
longitudinal axis upon deployment from the housing 310. The elastic blade
is shown having a clockwise spiral, but counterclockwise spirals, and
combinations of the two, are also appropriate for use herein.
FIG. 6-11 shows an elastic blade 336 which is sharply curved in the region
closest the housing 310, and substantially linear in the region furthest
from the housing 310.
FIG. 6-12 shows a standard surgical blade 350, which is attached to a strip
of elastic material 352 by a mechanical means 354. The standard surgical
blade 350 is not curved. However, the strip of elastic material 352 is
strongly bent, and upon deployment from the housing it acts to bend the
surgical blade 350 sharply away from the housing 310.
FIGS. 6-13 through 6-19 are each a top view of an alternate elastic blade
of this invention.
FIG. 6-13 shows a top view of an elastic blade 436 which has one
longitudinal sharpened (cutting) edge 460.
FIG. 6-14 shows a top view of an elastic blade 436 in which the entire
perimeter of the blade provides the sharpened edge 460.
FIG. 6-15 shows a top view of an elastic blade 436 in which only the most
distal surface provides the sharpened edge 460.
FIG. 6-16 shows a top view of an elastic blade 436 in which only the most
distal surface provides the sharpened edge 460. The sharpened edge 460 has
two angled sections, 460a and 460b, each of which is angled relative to
the longitudinal axis of the blade. The angled sections can have any
desired degree of angle relative to the longitudinal axis of the blade,
and the degree of angle for each section can be similar to, or dissimilar
to, that of the other section.
FIG. 6-17 shows a top view of an elastic blade 436 in which an outwardly
curved surface provides the sharpened edge 460.
FIG. 6-18 shows a top view of an elastic blade 436 in which an inwardly
curved surface provides the sharpened edge 460.
FIG. 6-19 shows a top view of a preferred embodiment of the elastic blade
436 in which the distal perimeter of the blade provides the sharpened edge
460, and the proximal edges of the blade are unsharpened. The width of
distal section of the elastic blade 436 is somewhat less than the width of
the proximal section. The distal portion of the elastic blade having the
sharpened edge 460 is narrower than proximal unsharpened portion, so that
the sharpened edge 460 will not touch the sides of the sheath bore. The
sharpened edge 460 is therefore protected during the process of deployment
and retraction of the elastic blade 436.
FIG. 6-20 shows a top view of an embodiment of the elastic blade 436 in
which all edges of the blade are unsharpened. This embodiment is preferred
when the blade is not used to cut tissues, and can function to manipulate
tissues or artificial devices.
The elastic blade is compressed and loaded within the sheath. In this
constrained configuration, the blade and sheath can be sterilized,
packaged and stored for later use.
In one preferred embodiment, a device of this invention comprises (a) a
housing having a distal deployment opening; (b) a curved elastic blade
which is linearly constrainable within the housing; and (c) remote means
to project and retract the elastic blade relative to the distal deployment
opening; the elastic blade being moveable between a first position wherein
the elastic blade is linearly constrained within the housing, and a second
position wherein the elastic blade is extended past the distal deployment
end and assumes a memory shape.
In a preferred embodiment, a blade of this invention comprises an
elastically deformable curved blade.
According to a seventh form of the present invention, it has now been
discovered that a pivoted two-bladed device, such as a forceps, scissors,
snips, and the like, can be combined with an elastically deformable stem.
Remote blade actuator means are used to cause the blades to splay apart or
come together. An elastic member and a constraining member, for deforming
the elastically deformable stem, are present. The elastic member and the
constraining means are longitudinally slidable relative to one another,
causing the angular deformation of the elastically deformable stem.
The elastically deformable stem includes an elastic member which is
substantially linear when it is constrained, and assumes a substantially
non-linear shape when it is unconstrained. When a constraining elongate
housing is present and serves as the constraining member, the elastic
member is moveable between a first position wherein the elastic member is
linearly constrained within the housing, and a second position wherein the
elastic member is deployed from the housing and is unconstrained.
Alternatively, the housing is moveable between a first position wherein
the elastic member is linearly constrained, and a second position wherein
the elastic member is unconstrained. The elastically deformable stem,
which includes the elastic member, assume a nonlinear shape. The amount of
deformation of the elastically deformable stem can be controlled by
adjusting the amount of the elastic member which is not constrained by the
elongate housing.
If the device does not include an elongate housing, and in embodiments in
which the elongate housing is present but is not a constraining member, an
internal constraining member is present. The deformation of the
elastically deformable stem can be controlled by moving the elastic member
between a first position wherein the elastic member is linearly
constrained, and a second position wherein the elastic member is
substantially unconstrained. Alternately, the deformation of the
elastically deformable stem can be controlled by moving the constraining
member between a first position wherein the elastic member is linearly
constrained, and a second position wherein the elastic member is
substantially unconstrained. Between the first, constrained, position and
the second, unconstrained, position, is a range of partial or variable
deployment.
The elastic member is formed of an elastic material, preferably a
pseudoelastic material such as a shape memory alloy, which is capable of
being greatly deformed without permanent deformation. This provides an
improved instrument that can be used in applications in which there is a
limited amount of space. The instrument can be operated remotely, and at
angles to the line of insertion, more conveniently than previous
instruments. The instrument, with appropriately configured blade edges
and/or tips, can be used to grasp, cut, and/or dissect tissue.
A remotely operated instrument of this invention comprises (a) a bladed
element having a first pivoted blade, and a second opposing blade; (b) an
elastically deformable stem connected to the bladed element, the
elastically deformable stem including an elastic member; (c) a
constraining member which can constrain the elastic member in a
substantially linear configuration; (d) a blade actuator means for
controlling pivotal motion of the pivotable blade(s); and (e) a stem
deforming means for controlling deformation of the elastically deformable
stem. A separate blade rotator means, for controlling rotation of the
plane through which the blade(s) are pivoted, is preferably included.
An alternate remotely operated instrument of this invention comprises: (a)
a bladed element, having opposable blades including a first blade which is
mounted for movement relative to the second blade; the first blade being
moveable between a closed position wherein the axes of the blades are
substantially parallel, and an open position, wherein the axes of the
blades are deflected from the parallel; (b) an elastically deformable stem
including an elastic member which is substantially non-linear in its
unconstrained shape; (c) a constraining member which constrains the
elastic member in a substantially linear shape; (d) a blade actuator
means, said blade actuator means controlling position of the opposing
blades between the open position and the closed position; and (e) a stem
deformation controlling means. A rotation means, for controlling the plane
of the blades, is preferably included.
The elastically deformable stem includes at least one elastic member which
assumes a linear configuration when constrained, and which is curved when
unconstrained. The elastic member is held in a constrained configuration
by the presence of the constraining member. Elastic materials which are
suitable for use in the elastic member include pseudoelastic and
superelastic materials, as described below.
When an elongate housing is present and acts as the constraining member,
the instrument is moveable between a first position wherein the
elastically deformable stem and, optionally, the bladed element, are are
within the housing, and a second position wherein the bladed element and
at least part of the elastically deformable stem are deployed from the
housing. The elastically deployable stem includes an elastic member which
is curved at a predetermined angle with respect to the elongate housing
when the elastically deformable stem is deployed from the housing. When
the housing acts as the constraining member, varying the amount of
deployment of the elastically deformable stem varies the angle of
presentation of the bladed element.
In an alternate embodiment, the elastic member is constrained in a linear
configuration by the action of an internal constraining member, such as an
internal constraining rod. Movement of the internal constraining member
relative to the elastic member causes variable deformation of the
elastically deformable stem. An elongate housing may or may not be present
in embodiments in which an internal constraining member is present.
The bladed instrument can comprise a grasping device (e.g., a forceps), a
cutting device (e.g., a scissors), or a dissecting device.
FIG. 7-1 shows an instrument of this invention.
FIGS. 7-2 show the deployment end of a bladed instrument of this invention.
FIGS. 7-3 and 7-4 are longitudinal cross-sectional views of alternate
elastically deployable stems, in longitudinally constrained and
longitudinally unconstrained configurations.
FIGS. 7-5 through 7--7 each show alternate views of an elastically
deformable stem of this invention.
FIGS. 7-8 and 7-9 show alternate elastic members suitable for use in an
elastically deformable stem of this invention.
FIGS. 7-10 show alternate views of a device of this invention having two
pivoted blades, each blade having a longitudinal slot proximal the pivot.
FIGS. 7-11 show alternate views of a device of this invention having two
blades, two bars, and four pivots.
FIGS. 7-12 show alternate cross-sections of the device of FIG. 7-1, taken
through line 12--12.
FIGS. 7-13 show various blades suitable for use herein.
FIGS. 7-14 show various blade cross-sections, taken through line 14--14 of
FIG. 7-13.
A surgical instrument of this invention consists essentially of: a bladed
element having opposable blades, at least one of which is pivotally
mounted for movement; a blade actuator means for causing pivotal motion of
the pivotable blade(s); an elastically deformable stem connected to the
bladed element; and a variable constraining means for causing deformation
of the elastically deformable stem.
The instrument is particularly useful in applications in which access to an
object to be cut, grasped, or dissected is restricted. For example, the
instrument is especially useful in medical applications in which the
object to be cut, grasped, or dissected is part of a human or animal body.
In such applications, the surgical instrument generally includes or is
passed through a sheath in the form of a cannula, catheter, or endoscope.
The distal end of the sheath is introduced through an opening into a body
cavity, duct, or joint, for example during laparoscopic surgery.
The instrument may also be useful in the assembly of mechanical, electrical
or other equipment, especially when access to the worksite is limited, or
when the worksite is located at an angle to the access.
The instrument includes an elastically deformable stem, so that the bladed
element can be variably angled away from the angle of introduction. When
an elongate housing (e.g., a sheath) is present, the bladed elements can
be arranged such that the axis on which the elements cut, grasp, and/or
dissect the object is not coaxial with the axis of at least a significant
portion of the elongate housing.
The elastically deformable stem includes at least one elastic member, which
is made of an elastic material. The elastic member is manufactured in a
non-linear shape. For example, the elastic member is manufactured having
one or more (generally one) bend, curve or twist. The bend, curve or twist
can describe any desired angle. The angle described by the elastic member
is generally less than 270.degree., more generally less than about
180.degree.. For many applications, an angle of about 90.degree. is
preferred. The angle described by the elastic member in its unconstrained
shape is the maximum amount of deformation which can be attained by the
elastically deformable stem.
The elastic member is deformed (constrained) from the bent configuration
towards the straight configuration, and held in the straight (constrained)
configuration during positioning of the instrument. Preferably, the bladed
element is fully functional when the blades are not housed within the
elongate housing, whether or not the elastically deformable stem has been
deployed. When the elastically deformable stem is to assume an angled
(unconstrained) configuration, the constraining member is removed. When
the elastically deformable stem is constrained by an elongate housing, the
housing is withdrawn to permit the elastic member to regain its bent
(unconstrained) shape, and thus deform the elastically deformable stem.
When the elastically deformable stem is constrained by a constraining rod,
for example, the rod is preferably withdrawn to permit the elastically
deformable stem to regain its bent (unconstrained) shape. Alternately, the
elastic member can be deployed beyond the constraining member to permit
the elastic member to assume its unconstrained shape and to deform the
elastically deformable stem.
The amount of deformation of the elastically deformable stem can be
variably controlled between the maximum and the minimum by manipulation of
the constraining member. The constraining means is generally a
longitudinally slidable rigid member. The constraining member can
comprise, for example, a stiff elongate housing, or a substantially linear
stiff constraining rod. Alternatively, the constraining member can be
fixed, and the elastic member can be slidable relative to the constraining
member.
The elastically deformable stem can be, for example, a rod, one or more
wires, a hollow tubular element, or the like.
When the instrument includes a housing which acts to constrain the elastic
member into a substantially linear shape, the housing and the elastically
deformable stem are moved longitudinally relative to each other to release
the elastic member from lateral constraint. The elastic member regains its
original (unconstrained) non-linear shape, and thus to deform the
elastically deformable stem. This approach is shown in graphic
cross-section in FIG. 7-3.
Alternatively, the elastically deformable stem can include a substantially
linear constraining rod. This constraining rod deforms the elastic member
into a substantially linear shape. As the constraining rod and the elastic
member are withdrawn relative to one another, the elastic member regains
its original non-linear shape and causes the elastically deformable stem
to deform. This approach is shown in graphic cross-section in FIG. 7-4.
In yet another embodiment (not shown), the instrument includes a
substantially linear constraining means which has a fixed position. This
constraining means deforms the elastic member into a substantially linear
shape. As the elastic member and the constraining rod are withdrawn
relative to one another, the elastic member regains its original
non-linear shape and causes the elastically deformable stem to deform.
The elastic member of the elastically deformable stem comprises an elastic
material which is substantially linear in its constrained configuration,
and is curved in its unconstrained, or "memory", configuration. The term
"elastic material" is used herein to mean a material that has spring-like
properties, that is, it is capable of being deformed by an applied stress
and then springing back, or recovering, to or toward its original
unstressed shape or configuration when the stress is removed. The elastic
material is preferably highly elastic. The material can be polymeric or
metallic, or a combination of both. The use of metals, such as shape
memory alloys, is preferred. Shape memory alloys that exhibit
pseudoelasticity, in particular superelasticity, are especially preferred.
The elastic materials herein exhibit greater than 1% elastic deformation,
more generally greater than 2% elastic deformation. Preferably, the
elastic materials herein exhibit greater than 4% elastic deformation, more
preferably greater than 6% elastic deformation.
Preferably, the elastic member is at least partially formed from a
pseudoelastic material, such as a shape memory alloy.
The Figures are drawn for clarity and are not drawn to scale.
FIG. 7-1 shows a bladed instrument of this invention. As shown, a
scissors-type blade actuator mechanism 110 controls the pivotal movement
of the blades 112. A finger-activated stem deformation controlling means
114 is used to control the deployment of the bladed element 116 and the
elastically deformable stem 118 from the elongate housing 120. A rotator
mechanism 122 is shown in the form of a knob, and is used to rotate the
elastically deformable stem 118 and the bladed element 116 around the long
axis of the elongate housing .beta.. Each of the actuator mechanism 110,
the stem deformation controlling means 114, and the rotator mechanism 122
can take any suitable manually operated configuration. The specific
configuration of each of the actuator mechanism 110, the stem deformation
controlling means 114, and the rotator mechanism 122 can be the same, or
they can be different, as shown. Examples of suitable manually operated
mechanisms include one or more slider, pistol grip handle, scissors
handle, and/or plunger arrangement. These and other such devices are well
known to the art.
An elongate housing 120 maintains the elastic member 124 in a substantially
linear configuration prior to deployment of the elastically deformable
stem 118 and the bladed element 116. Upon full deployment from the
elongate housing, the bladed element 116 assumes a position which is at an
angle from the elongate housing 120. It should be noted that the angle
.phi. between the elongate housing 120 and the bladed element 116 can be
any number of degrees desired. As shown, angle .phi. is approximately
60.degree.. Angle .phi. is defined by the axis of the elongate housing
.beta., and the plane which is perpendicular to the axis of the pivot 126
around which the blades pivot. Angle .phi. can be any desired angle.
Preferably a rotator mechanism 122 is provided, and permits rotation of
the bladed element 116 and the elastically deformable stem 118 around the
long axis of the elongate housing .beta.. The rotation of the bladed
element 116 is preferably independent of the amount of deployment of the
elastically deformable stem 118.
The elongate housing 120 is an elongate sheath having an axial bore (not
shown) therethrough. The axial bore is sized to receive the elastically
deformable stem and, optionally, the bladed element, in a constrained
configuration. The axial bore can have a consistent dimension through the
length of the elongate housing 120, or the axial bore can widen and narrow
as necessary to conform to the shape of the elastically deformable stem
118 and, optionally, to the bladed element 116.
In general, the elongate housing 120 can be flexible or rigid, and the
rigidity can vary by region. When the elongate housing does not act as the
constraining member, an alternate constraining member (such as an internal
constraint) must be present. Standard catheters and laparoscopic devices
well known to the art are appropriate housings for the bladed element and
the elastically deformable stem. The stiff-sheath elongate housing of FIG.
7-1 can be polymeric or metallic, for example stainless steel. A preferred
stiff elongate housing is a rigid elongate tube of stainless steel.
The elongate housing 120 can be circular in cross-section, but other
cross-sections may be preferable in some situations. For example, squared,
oval, or eccentric cross-sections can be used. The elongate housing can be
substantially uniform in cross-section along its length, or it can vary.
The specific configuration and dimensions of the elongate housing 120 will
vary with the use of the device, the parameters of the bladed element, and
whether access for additional surgical devices is provided. The outer
diameter of the elongate housing will vary with the application and the
size of the bladed element. For example, the elongate housing in a
laparoscopic device will have a diameter of from less than about 3 mm to
about 1.5 cm or greater; the length of a laparoscopic device will be from
less than about 20 cm to about 30 cm or greater.
In any of the embodiments of this invention, a suitable means may be
provided for passing a fluid (liquid or gas) through the device for
irrigation, aspiration, insufflation, and the like. In any of the
embodiments of this invention, electricity may be passed to one or both
end portion(s) of the blade(s) for purposes of electrocautery or
electrocutting.
FIGS. 7-2A through 7-2D are side views of the distal end of an instrument
of this invention. The instrument shown in FIG. 7-2 includes a rigid
elongate housing 128 which acts as the constraining means.
As shown in FIG. 7-2, the instrument is moveable between a first position
(FIG. 7-2A or FIG. 7-2B) wherein the elastically deformable stem 132 is
constrained within the elongate housing 128, and a second position (FIG.
7-2D) wherein the bladed element 130 and the elastically deformable stem
132 extend past the constraint of the elongate housing 128 and assume a
memory shape. In one embodiment, both the elastically deformable stem 132
and the bladed element 130 are fully retractable into the elongate housing
128, as shown in FIG. 7-2A. Between the first position and that shown in
FIG. 7-2D are degrees of deployment (for example that shown in FIGS. 7-2B
and 7-2C) in which the bladed element 130 is deployed sufficiently for use
(FIG. 7-2B), and in which the elastically deformable stem 132 is partially
deployed (FIG. 7-2C). In an alternate embodiment, the bladed element 130
is not retractable into the elongate housing 128. Such an embodiment is
demonstrated in FIGS. 72B through 7-2D. These variable degrees of partial
deployment allow the operator to choose the angle of deflection that the
bladed element assumes relative to the elongate housing 128. (Pivotal
actuation of the blades is not shown in this series of figures.)
After use, the instrument is removed from the worksite. When the worksite
is within a patient, the elastically deformable stem 132 and, optionally,
the bladed element 130, are retracted back into the elongate housing 128
before the instrument is removed from the patient: the various elements
therefore resume the configuration shown in FIG. 7-2A before removal. If
only the elastically deformable stem 132 is retracted back into the
elongate housing 128 before the instrument is removed from the patient,
the elements resume the configuration shown in FIG. 7-2B before removal.
FIG. 7-2B shows the blades 134 free of the elongate housing 128. The blades
134, the pivot 136, and other elements necessary for pivotal motion of one
or more blade (but not including the blade actuator) comprise the bladed
element 130. A portion of the elastic member 138 is shown. In the pictured
embodiment, the elastic member 138 comprises two strips of elastic
material, each strip being secured to the pivot 136. The elastic member
138 can have any desired cross-sectional shape, and the cross-sectional
shape can vary along its length. Preferred cross-sectional shapes include
a tubular shape or rod shape, and a rectangular or roughly rectangular
shape. In the embodiment shown the elastic member 138 comprises two strips
which are not in the neutral plane of bending of the elastically
deformable stem 132: this is a less preferred configuration. The preferred
placement of the elastic member is at or near the neutral plane of bending
of the elastically deformable stem 132, and is discussed further below.
FIG. 7-2C shows the bladed element 130 as it is deployed axially from the
elongate housing 128. Also shown is a portion of the elastic member 138.
Shown next to the elastic member 138 is the blade actuator rod 140. In
this embodiment, the elastic member 138 and the blade actuator rod 140 are
included within the elastically deformable stem 132. The actuator rod 140
is preferably centrally located within the elastically deformable stem.
The blade actuator rod 140 can comprise a rod, strip, filament, cord,
conduit, catheter, pipe, lever, or other suitable connecting means which
allows the remote pivotal manipulation of the blade(s). More than one such
element can be present. The cross-sectional parameters of the blade
actuator rod can vary along its length. Any suitable material, including a
shape-memory material, can be used to form the blade actuator rod 140. In
one embodiment, the elastic member also acts as the blade actuator rod
140. The blade actuator rod 140 preferably has sufficient flexibility that
it does not interfere with the elastic deformation of the elastic member
138. The blade actuator rod 140 can be positioned as desired within the
elastically deformable stem 132. Preferably, the blade actuator rod 140 is
located in a position that does not interfere with the longitudinal motion
of the elastic member 138 or of the constraining member, and does not
interfere with the bending motion of the elastic member 138. At the
actuator end of the instrument (not shown), the blade actuator rod 140 can
integrate with an actuator means, such as a slider mechanism, pistol grip
or thumb actuated mechanism, scissors handle, and/or plunger mechanism.
Alternatively, the actuator rod 140 projects proximally from the elongate
housing 128, and can be directly manipulated to cause pivotal motion of
the opposing blades. The blade actuator means includes the actuator rod
140, any apparatus necessary to integrate with the bladed element, and the
actuator mechanism (if any). The blade actuator means is used remotely to
open and close the bladed element. Illustrative actuating means are
described more fully below with reference to the drawings and include rack
and pinion means, pin and slot means, four-bar linkages, and the like. In
certain embodiments, the actuating means may be formed of a pseudoelastic
material. The actuating means may permit the bladed element to be axially
rotated. The actuating means can also provide suitable means for
irrigating or aspirating the workfield of the bladed elements, or can
conduct electrical current to one or both of the blades, if desired.
FIG. 7-2D shows the bladed element 130 in the fully deployed configuration.
The elastically deformable stem 132 is fully deployed (i.e,, has achieved
its fully unconstrained shape), and, as depicted, holds the bladed element
130 in position approximately 90.degree. from the axis of the body of the
instrument.
Reconstraining the elastically deformable stem 132 as shown in FIG. 7-2D is
accomplished by reversing the process, i.e., by moving the elements to the
configuration shown in FIGS. 7-2C, 7-2B, and (optionally) 7-2A,
sequentially.
FIG. 7-3 provides cross-sectional views of one segment of an elastically
deformable stem 142 in constrained (FIG. 7-3A), partially constrained
(FIG. 7-3B), and unconstrained (FIG. 7-3C) configurations.
FIG. 7-3A shows a section of an elongate housing 144 which surrounds the
elastically deformable stem 142. The elastically deformable stem 142 is
fully constrained by the elongate housing 144, and is in a substantially
linear configuration. The elastically deformable stem 142 includes an
elastic member 146 in the shape of a a tube, and the enclosed blade
actuator rod 148.
The elongate housing 144 and the elastically deformable stem 142 are
capable of reciprocal longitudinal motion, e.g., are longitudinally
slidable relative to one another. For example, the elongate housing 144
can be moved in direction L (arrow) to deploy the elastically deformable
stem 142. The same effect can be achieved by moving the elastically
deformable stem 142 in direction R (arrow). Alternatively, the elongate
housing 144 can be moved in direction L (arrow) while the elastically
deformable stem 142 is moved in direction R (arrow), to achieve deployment
of the elastically deformable stem 142. Point a is labeled on FIGS. 7-3A,
7-3B and 7-3C, and shows the relative movement of the elastically
deformable stem 142 relative to the elongate housing 144.
FIG. 7-3B shows the section of elastically deformable stem 142 in a
partially deployed configuration. The elastically deformable stem 142 is
partially constrained in a linear configuration by the elongate housing
144, and partially unconstrained.
FIG. 7-3C shows the section of elastically deformable stem 142 in a fully
deployed configuration. The elastically deformable stem 142 is
unconstrained, and shows the maximum deformation available from the
specific elastic member 146.
Reconstraining the elastically deformable stem 142 as shown in FIG. 7-3C is
accomplished by reversing the process, i.e., by moving the elements to the
configuration shown in FIGS. 7-3B and 7-3A, sequentially.
FIG. 7-4 provides views of one segment of an elastically deployable stem
150 in constrained (FIG. 7-4A), partially constrained (FIG. 7-4B), and
unconstrained (FIG. 7-4C) configurations.
FIG. 7-4A shows a section of an elastically deformable stem 150 which is
constrained by the constraining rod 152, and is held in a substantially
linear configuration. The elastically deformable stem 150 comprises an
elastic member 154, the blade actuator rod 156, and the constraining rod
152.
The constraining rod 152 and the elastically deformable stem 150 are
longitudinally slidable relative to one another. For example, the
constraining rod 152 can be moved in direction L (arrow) to cause
deformation of the elastically deformable stem 150. The same effect can be
achieved by moving the elastically deformable stem 150 in direction R
(arrow). Alternatively, the constraining rod 152 can be moved in direction
L (arrow) while the elastically deformable stem 150 is simultaneously
moved in direction R (arrow), to achieve deformation of the elastically
deformable stem 150. Point b is labeled on FIGS. 7-4A, 7-4B and 7-4C, and
shows the relative movement of the elastically deformable stem 150
relative to the constraining rod 152.
FIG. 7-4B shows the section of elastically deformable stem 150 in a
partially deployed configuration. The elastically deformable stem 150 is
partially constrained in a linear configuration by the constraining rod
152, and partially unconstrained.
FIG. 7-4C shows the section of elastically deformable stem 150 in a fully
deployed configuration. The elastically deformable stem 150 is
unconstrained, and shows the maximum deformation available from the
specific elastic member 154.
Reconstraining the elastically deformable stem 150 as shown in FIG. 7-4C is
accomplished by reversing the process, i.e., by moving the elements to the
configuration shown in FIGS. 7-4B and 7-4A, sequentially.
In one embodiment (not shown) the elastically deformable stem and the rigid
constraining rod are present only at the distal (introduced) end of the
instrument, near the bladed element. The major portion of the introduced
body of the instrument is relatively flexible. Such an embodiment finds
particular use as an endoscopic device, i.e., a device which can be
introduced through naturally occurring openings. In the human body,
endoscopic devices are appropriate for use in the respiratory tract
(introduced through the mouth or nose), gastrointestinal tract (introduced
through the mouth, nose, or rectum), or in the urogenital tract
(introduced through the ureter or, in women, the vagina).
The material of the flexible housing of the endoscopic instrument may be
polymeric. If made of a flexible polymeric material, the material may be
reinforced, for example, with fibers. A suitable polymeric material for
the component is, for example, polytetrafluoroethylene, reinforced with
braided fibers.
The elongate housing in an endoscopic device will have a diameter of from
less than about 0.7 mm to about 4.5 cm or greater; the length of
endoscopic devices will be from less than about 10 cm to about 3 meters or
greater.
FIGS. 7-5 through 7--7 each show a different embodiment of the elastically
deformable stem of this invention.
FIG. 7-5A shows a portion of an elastically deformable stem 158 and of an
elongate housing 160. Shown in cutaway view are the blades 162 and the
pivot 164, sheathed within the elastically deformable stem 158. In the
shown embodiment, the blades 162 must be deployed from the elastic member
166 prior to pivotal blade movement, controlled by the blade actuator rod
168. The plane through which the blades 162 open can be in any orientation
desired relative to the elastically deformable stem 158 or to the elongate
housing 160.
FIG. 7-5B shows a cross-sectional view of the elastically deformable stem
158, taken through line 5b--5b of FIG. 7-5A. The blade actuator rod 168 is
fully enclosed by the elastic member 166.
FIG. 7-6A shows a portion of an elastically deformable stem 170 having a
rod-and-groove configuration, and of an elongate housing 172. The blade
actuator rod 174 is partially enclosed by the elastic member 176, and is
partially exposed.
FIG. 7-6A shows an embodiment wherein the blades 178 and the pivot 180 are
not substantially sheathed within the elastically deformable stem 170 when
the elastically deformable stem 170 is fully withdrawn into the housing
172. The blades 178 do not need to be deployed from the elastic member
prior to pivotal blade movement, controlled by the blade actuator rod 174.
The plane through which the blades 178 open can be in any orientation
desired relative to the elastically deformable stem 170 or to the elongate
housing 172.
FIG. 7-6B shows a cross-sectional view of the elastically deformable stem
170, taken through line 6b--6b of FIG. 7-6A. The blade actuator rod 174 is
partially enclosed in a groove in the elastic member 176.
FIG. 7-7A shows a portion of a housing 182, and an elastically deformable
stem 184 with a windowed configuration. The windows are shown on the
convex surface of the elastically deformable stem 184. Such windows can be
present on any of the concave or lateral surfaces of the elastically
deformable stem 184, as desired. Any number of windows can be used,
including one, two, or a multiplicity.
Shown in cutaway view are curved blades 190 and the pivot 192, which are
substantially sheathed within the elastically deformable stem 184. As
shown, the blades 190 must be deployed prior to pivotal blade movement.
When the blades 190 are curved, it is generally preferable that the curve
of the blades 190 continue the curve of the elastically deformable stem
184, but that is not necessary.
The plane through which the blades 190 open can be in any orientation
desired to the elastically deformable stem 184, or to the elongate housing
182. In a currently preferred embodiment, the blades 190 are not retracted
into the elongate housing 182 or into the elastically deformable stem 184
even when the blades are fully retracted, a configuration which is shown
in FIG. 7-2B.
FIG. 7-7B shows a cross-sectional view of the elastically deformable stem
184, taken through line 7b--7b of FIG. 7-7A. The blade actuator rod 186 is
partially enclosed in a groove in the elastic member 188.
FIG. 7-7C shows a cross-sectional view of the elastically deformable stem
184, taken through line 7c--7c of FIG. 7-7A. The blade actuator rod 186 is
fully enclosed by the elastic member 188.
FIG. 7-8 demonstrates the use of an alternate elastic member 194. As shown
in FIG. 7-8A, the elastic member 194 is an element such as a wire which
describes a closed shape in its unconstrained shape. The elastic member
194 has a stem 196, which can be a continuation of the elastic member 194,
as shown, or can be a handle means connected to the elastic member 194.
Point g and point h are labeled to show the progression of the loop as it
is withdrawn into the constraining housing 198. FIG. 7-8B demonstrates
that when the stem 196 and the elastic member 194 are retracted into a
constraining housing 198, the circle deforms into a cupped configuration.
As shown in FIG. 7-8C, further retraction of the stem 196 and the elastic
member 194 into the constraining housing 198 causes further deformation.
The closed shape becomes narrowed and sharply angled. This occurs because
as the sides of the closed shape take less stress to rotate out of the
plane of the undeformed shape than to straighten within the plane of the
undeformed shape. The figure thus deforms by bending at the apex, with the
sides rotating out of the plane of the undeformed shape.
FIGS. 7-8D, 7-8E and 7-8F show the incorporation of the closed shape of
FIGS. 7-8A, 7-8B and 7-8C, respectively, into an enclosing flexible sheath
200. FIGS. 7-8D, 7-8E and 7-8F are side views of the flexible sheath 200
and constraining housing 198 which show the bending which takes place as
the stem (not shown) and the circular elastic member (not shown) are drawn
into the constraining housing 198.
FIG. 7-9 demonstrates another method of constraining an elastic member.
FIG. 7-9A shows two unconstrained elastic members 202a and 202b. Each is
curved when it is not constrained. Each is capable of independent
rotation. As shown in FIG. 7-9A, the elastic members 202a and 202b are
angled away from each other.
FIG. 7-9B shows the elastic members 202a and 202b held within a flexible
sheath 204. The sheath causes each elastic member to act as a constraint
for the elastic member having an opposite bend. As a result, the flexible
sheath 204 is straight.
FIG. 7-9C shows the elastic members 202a and 202b held within a flexible
sheath 204. Elastic member 202b has been rotated to align its curve to the
curve of elastic member 202a. The sheath bends to conform to the bend of
the two elastic members 202a and 202b.
FIGS. 7-9D through 7-9F graphically represent the forces involved in FIGS.
7-9A through 7-9C, respectively, as represented in top view.
FIG. 7-9D depicts vectors for the elastic members 202a and 202b, as shown
in FIG. 7-9A. Elastic member 202a is shown as a vector arrow pointing to
the left; elastic member 202b is shown as a vector arrow pointing to the
right.
FIG. 7-9E depicts vectors for the elastic members 202a and 202b as shown in
FIG. 7-9B. The flexible sheath 204 is shown. The flexible sheath 204 does
not curve, as the forces exerted by the elastic member 202a are cancelled
out by the forces exerted by elastic member 202b.
FIG. 7-9F depicts vectors for the elastic members 202a and 202b, as shown
in FIG. 7-9C. The flexible sheath 204 is shown. The flexible sheath 204
curves to the left, represented by the resultant arrow 205. The vector
forces exerted by the elastic member 202a are reinforced by the vector
forces exerted by elastic member 202b.
FIG. 7-9G depicts alternate vectors for elastic members 202a and 202b. The
flexible sheath 204 is shown. Elastic member 202a is represented by a
vector leftward, while elastic member 202b is represented by a vector
which is at a 90.degree. angle from that of elastic member 202a. The
forces exerted by the elastic member 202a are only partially reinforced by
the forces exerted by elastic member 202b. The flexible sheath 204 curves
to the upper left, represented by the resultant arrow 206.
FIG. 7-9H depicts another vector set for elastic members 202a and 202b. The
flexible sheath 204 is shown. Elastic member 202a is represented by a
vector downward, while elastic member 202b is represented by a vector to
the right. The forces exerted by the elastic member 202a are only
partially reinforced by the forces exerted by elastic member 202b. The
flexible sheath 204 curves to the lower right, represented by the
resultant arrow 207.
FIG. 7-9I depicts yet another vector set for elastic members 202a and 202b,
The flexible sheath 204 is shown. Elastic member 202a is represented by a
vector downward, as is elastic member 202b. The forces exerted by the
elastic member 202a are reinforced by the forces exerted by elastic member
202b. The flexible sheath 204 curves to the bottom, represented by the
resultant arrow 208. By rotation of one or more of the elastic members
202a and 202b, the flexible sheath 204 can be curved through a 360.degree.
circle,
FIG. 7-10 shows a device of this invention having two pivoted blades, each
blade having a longitudinal slot next to the pivot.
FIG. 7-10A is a side view of an instrument in the unconstrained
configuration with a partial cutaway near the bladed element. A bend of
approximately 90.degree. is present in the elastically deformable stem
210. The actuating rod 212 is enclosed within the elastic member 214. The
movement of the actuating rod 212 and of the elastically deformable stem
210 are preferably independent, and each is controlled by longitudinal
motion of the proximal ends. Opening and closing of the blades is caused
by reciprocal motion of the proximal portion of the actuating rod 216.
Deflection of the elastically deformable stem 210 is caused by reciprocal
motion relative to the elongate housing 220 of the proximal portion of the
elastically deformable stem 218.
FIG. 7-10B shows a cut-away top view of the instrument of FIG. 7-10A. Two
blades 222a and 222b are present. As shown, each blade is V-shaped. In a
preferred embodiment, not shown, each blade is substantially straight. A
pivot 224 is present intermediate to the ends of the blade. The pivot
allows pivotal motion of the two blades, and holds the blades in position
on the elastically deformable stem. A longitudinal slot 226 is present in
each blade proximal to the pivot. The two blades 222a and 222b are
moveable between a closed position, wherein the axes of the distal
portions of the blades are substantially parallel, and an open position,
wherein the axes of the distal portions of the blades are deflected from
the parallel, Pivotal movement of the blades 222 is caused by a sliding
pin (not shown) which is part of the actuator rod 212, and which
integrates with the longitudinal slot 226 present in each of the blades,
In alternate embodiments, the blades can be located partially within the
elastically deformable stem; the blades can be fixed to opposite sides of
the elastically deformable stem; or the blades can be fixed to a concave,
convex, or lateral edge of the elastically deformable stem. The pivotal
connection shown is for demonstration purposes only, and any appropriate
toggle, gear, or pivotal connection can be used.
FIG. 7-11A shows a longitudinal cross-sectional view of an instrument in
the unconstrained configuration. The bladed element 228 includes two
blades, two bars, and four pivots. A bend of approximately 90.degree. is
present in the elastically deformable stem 230. The actuating rod 232 is
enclosed within the elastic member 234. The movement of the actuating rod
232 and of the elastically deformable stem 230 are each controlled by
longitudinal motion of the proximal ends. Opening and closing of the
blades is caused by reciprocal motion of the proximal portion of the
actuating rod 236. Deflection of the elastically deformable stem 230 is
caused by reciprocal motion of the proximal portion of the elastically
deformable stem 238 relative to the elongate housing 240.
FIGS. 7-11B and 7-11C show cut-away top views of the instrument of FIG.
7-11A. Two blades 242a and 242b are present. Two bars 244a and 244b are
present. A pivot 246a is present intermediate to the ends of the blades
242a and 242b, joining the blades and attaching the blades to the
elastically deformable stem 230. Two pivots 246bare present at the
proximal ends of the blades 242a and 242b, where they join the distal ends
of bars 244a and 244b. A pivot 246c is present at the proximal end of the
bars 244a and 244b, joining the bars. Pivotal movement of the blades 242a
and 242b is caused by a sliding motion of the blade actuating rod 232.
FIG. 7-11B shows the blades in a relatively closed configuration. FIG.
7-11C shows the blades in a relatively open configuration.
FIGS. 7-12A through 7-12F show alternate cross-sections of an elastically
deformable stem of the instrument of FIG. 7-1, taken through line 12--12.
FIG. 7-12A shows an elastic member 248 and a blade actuator rod 250 within
a flexible material 252. The flexible material 252 describes a squared
pyramid shape in cross-section. The elastic member 248 and the blade
actuator rod 250 each comprise a strip of material which is roughly oval
in cross-section.
The use of a flexible material 252 which encloses an elastic member 248 and
a blade actuator rod 250 permits the easy use of one or more elastic
member 248 and/or blade actuator rod 250 members which is eccentrically
shaped in cross-section. Additionally, the material of the flexible
material 252 is generally less expensive and easier to work than the
material of either the elastic member 248 or the blade actuator rod 250.
The flexible material 252 can be, for example, a flexible polymer, or a
braided, coiled, segmented, hinged, or zig-zagged metal component. If made
of a flexible polymeric material, the material may be reinforced, for
example, with fibers, to enable it to withstand the forces exerted on it
by the elastic member while it is constrained within and deformed by the
elongate housing. A suitable polymeric material for the component is, for
example, polytetrafluoroethylene, optionally reinforced with braided
fibers.
The preferred cross-sectional embodiments include the actuator rod in or
close to the neutral plane, i.e., that plane which is neither compressed
nor stretched during the bending of the elastically deformable stem, FIGS.
7-12A through 7-12F are each labeled with a plane z--z, representing a
preferred neutral plane; and with a plane n--n, representing a preferred
plane through which the elastically deformable stem bends.
FIG. 7-12B shows two elastic members 248 on either side of an actuator rod
250, within a flexible material 252. The flexible material 252 is a
rounded rectangle in cross-section. The elastic members 248 are rods which
are round in cross-section, and the blade actuator rod 250 comprises a
strip of material which is oval in cross-section.
FIG. 7-12C shows two elastic members 248 on either side of an actuator rod
250, within a flexible material 252. The flexible material 252 has an oval
cross-section. The elastic members 248 are square in cross-section. The
blade actuator rod 250 is a rod which is round in cross-section.
FIG. 7-12D shows two elastic members 248 on either side of an actuator rod
250, within a flexible material 252. The flexible material 252 has an oval
cross-section. The elastic members 248 are square in cross-section, The
blade actuator rod 250 is a piece which resembles a rounded "H" in
cross-section. In an alternate embodiment, not shown, the blade actuator
rod includes a third elastic member within it, and the blade actuator rod
slides freely along the third elastic member. In another embodiment, not
shown, the elastic members and the actuator rod are held in position
without the action of a flexible material. In yet another embodiment, the
elastic member is intermediate to two blade actuator rods.
FIG. 7-12E shows an elastic member 248 and a blade actuator rod 250 within
a flexible material 252. The flexible material 252 has a squared pyramid
shape in cross-section. The elastic member 248 comprises a strip of
material which is rectangular in cross-section. The blade actuator rod 250
comprises a strip of material which is round in cross-section.
FIG. 7-12F shows an elastic member 248, a constraining rod 254, and an
actuator rod 250, within a flexible material 252. The flexible material
252 has a squared cross-section. The elastic member 248, the constraining
rod 254, and the actuator rod 250 are each oval in cross-section. Note
that the constraining rod is not within the neutral axis: only in the
absence of the constraining rod does the elastic member 248 assume its
unconstrained (bent) configuration. A configuration such as that shown in
FIG. 7-7F can be used in embodiments which do not include an elongate
housing. A lumen 255 is present. The lumen 255 can be used, for example,
to provide access for one or more apparatus for irrigation, aspiration,
cautery, and the like.
FIG. 7-13 shows a bladed element in which only one pivoting blade 256 is
mounted for pivotal motion, The pivoting blade 256 is biased in the open
(splayed) position by a spring 258. The fixed blade 260 is mounted in a
fixed position. The pivoting blade is closed by longitudinal motion of the
actuator rod 262. The housing 264 is shown in partial cutaway view.
Preferred embodiments of this invention include a symmetrical blade action,
so that both of the blades are actuated by the manually operated mechanism
and dissection, cutting, and/or grasping is done by symmetrical motion of
the two blades. However, in some situations, it may be desirable to have
embodiments in which one blade is moved more by the manually operated
mechanism than the other blade. In some cases, it may be desirable to have
one blade function as a stationary (and therefore passive) blade, where
the manually operated mechanism moves only the other blade.
The blades of this invention can be made of any appropriate material.
Metals known for scissor, knife, and/or forceps use are appropriate.
Stainless steel, for example, can be used. Rigid plastics can also be
used.
One use of the instruments of this invention involves cutting, e.g, when
one or more of the opposable blade provides a cutting edge. The honing of
an edge to form a cutting blade is well known in the art. If desired, the
cutting blade can be serrated, The cutting edge is preferably derived-from
beveling blade material itself. However, it may be desirable or necessary
to provide a honed edge of a secondary material to the blade material. For
example, a non-cutting plastic blade can be combined with an alloy cutting
edge. A cutting surface can be provided at any desired exposed edge of the
blade.
The blades can be straight, or they can be curved along their length, as
shown in FIG. 7-7A. When curved blades are present, the curved blades are
preferably made of an elastic material as described above.
FIG. 7-13B shows a cutting blade 266 which has one longitudinal cutting
edge 268.
FIG. 7-13C shows cutting blade 266 in which the perimeter of the blade
provides the cutting edge 268.
FIG. 7-13D shows a blade 266 which has no cutting edges. The end portion of
the blade is pointed to facilitate dissection of tissues.
FIG. 713E shows a blade 266 which has no cutting edges. The end portion of
the blade is curved.
FIGS. 7-14A through 7-14E show various blade cross-sections, taken through
line 14--14 of FIG. 7-13A. The cutting surfaces of the blades may abut one
another in the manner of wire cutters, or they may cross one another in
the manner of shears. The grasping surfaces of the blades may abut one
another and be sufficiently blunt to avoid cutting the object to be
grasped. Alternatively, the grasping surfaces need not be configured so as
to contact each other in the manner of cutting devices. The object being
grasped need merely be entrapped between the end portions of the blades.
The grasping surfaces may be ridged or contain protuberances to assist in
grasping the object.
FIG. 7-14A shows a cross-sectional view of two opposing blades. The blades
am roughly rectangular in cross-section. The blades meet at a flattened
surface, and are appropriate for grasping objects.
FIG. 7-14B shows a cross-sectional view of two opposing ridged blades. The
blades are roughly rectangular in cross-section. The blades meet at a
ridged surface, and are especially appropriate for grasping objects.
FIG. 7-14C shows a cross-sectional view of two opposing blades in which the
blades are not symmetrical. One blade is roughly rectangular in
cross-section, while the other blade is triangular. Such a configuration
is appropriate for cutting objects.
FIG. 7-14D shows a cross-sectional view of two opposing cutting blades. The
blades are roughly triangular in cross-section. The blades meet at a
pointed cutting surface.
FIG. 7-4E shows a cross-sectional view of two opposing cutting blades. The
blades are roughly triangular in cross-section. The blades meet and slide
along their surfaces in the manner of shears.
An eighth form of the present invention provides a device for dissecting an
object which comprises at least two elongate elements, positioned
alongside one another, each having a body portion and an end portion, the
end portions of the elements:
i being capable of being splayed apart from one another when free of
transverse constraint to dissect said object from surrounding material;
and
ii being capable of being moved toward one another;
wherein a portion of at least one of the elements is formed from a
pseudoelastic material.
In another aspect, the eighth form of the present invention provides a
device for grasping or cutting an object which comprises at least two
elongate elements, positioned alongside one another, each having a body
portion and an end portion, the end portions of the elements:
(i) being capable of being splayed outwardly apart from one another when
free of transverse constraint and presenting grasping or cutting surfaces
to an object to be grasped or cut that is placed between them; and
(ii) being capable of being moved inwardly towards one another to grasp or
cut said object;
wherein a portion of at least one of the elements is formed from a
pseudoelastic material.
A further aspect of the eighth form of this invention comprises a device
(or dissecting an object which comprises
a. at least two elongate elements, positioned alongside one another, each
having a body portion and an end portion, the end portions of the
elements:
i. being capable of being splayed apart from one another when free of
transverse constraint for dissecting said object from surrounding
material; and
ii. being capable of being moved toward one another; and
b. actuating means;
wherein a portion of at least one of the elements and/or said actuating
means is formed from a pseudoelastic material.
Another aspect of the eighth form of this invention comprises a device for
grasping or cutting an object which comprises
(a) at least two elongate elements, positioned alongside one another, each
having a body portion and an end portion, the end portions of the
elements:
(i) being capable of being splayed outwardly apart from one another when
free of transverse constraint and presenting grasping or cutting surfaces
to an object to be grasped or cut that is placed between them; and
(ii) being capable of being moved inwardly towards one another to grasp or
cut said object; and
(b) actuating means;
wherein a portion of at least one of the elements and/or said actuating
means is formed from a pseudoelastic material.
A further aspect of the eighth form of this invention comprises a device
for dissecting an object which comprises
a. a hollow elongate component; and
b. at least two elongate elements, at least part of which are positioned
within said component, said elements being positioned alongside one
another, each having a body portion and an end portion, the end portions
of the elements:
i. being capable of being splayed apart from one another when free of
transverse constraint; and
ii. being capable of being moved toward one another;
wherein the elements and the component are longitudinally slideable
relative to one another so that at least the end portions of the elements
can be slid into and out of said component and wherein a portion of at
least one of the elements is formed from a pseudoelastic material.
Yet another aspect of the eighth form of this invention comprises a device
for grasping or cutting an object which comprises
(a) a hollow elongate component;
(a) at least two elongate elements, at least part of which are positioned
within said component, said elements being positioned alongside one
another, each having a body portion and an end portion, the end portions
of the elements:
(i) being capable of being splayed outwardly apart from one another when
free of transverse constraint and presenting grasping or cutting surfaces
to an object to be grasped or cut that is placed between them; and
(ii) being capable of being moved inwardly towards one another to grasp or
cut said object;
wherein the elements and the component are longitudinally slideable
relative to one another so that at least the end portions of the elements
can be slid into and out of said component and wherein a portion of at
least one of the elements is formed from a pseudoelastic material which
can be deformed when under an applied stress.
A still further aspect of the eighth form of this invention comprises a
method of dissecting an object from surrounding material, which comprises:
A. providing a device which comprises at least two elongate elements,
positioned alongside one another, each having a body portion and an end
portion, the end portions of the elements being capable of being splayed
apart from one another when free of transverse constraint to dissect said
object from surrounding material; and wherein a portion of at least one of
the elements is formed from a pseudoelastic material;
B. positioning end portions adjacent the object; and
C. causing said end portions to splay apart so as to dissect said object
from surrounding material.
A further aspect of the eighth form of this invention comprises a method of
grasping or cutting an object, which comprises:
i. providing any one of the cutting or grasping devices as described above;
ii. positioning the object between splayed apart end portions of the
elements; and
iii. causing said end portions to move toward one another so as to grasp or
cut said object.
The pseudoelastic material used in any of the aspects of this eighth form
of the invention is preferably a shape memory alloy, such as a
nickel/titanium-based alloy, as discussed hereinbefore. The pseudoelastic
material may be, for example, a superelastic material, especially a
superelastic shape memory alloy.
Where the device according to the invention comprises a hollow component
this may be in the form of an elongate polymeric or metal tube.
According to two various aspects of the invention, at least a portion of at
least one of the elongate elements exhibits pseudoelasticity. For example
the end portion, or instead or in addition at least part of the body
portion, of at least one of the elements, may be formed from a shape
memory alloy which exhibits pseudoelasticity, especially superelasticity.
FIG. 8-1 is an isometric view of a device of the invention;
FIGS. 8-2A to 8-2C are cross-sections through the device shown in FIG. 8-1,
taken at lines A--A, B--B and C--C respectively;
FIGS. 8-3A to 8-3E are elevational views of a first embodiment Of the
device shown in FIG. 8-1 at various stages during a cutting operation;
FIGS. 8-4A to 8-4C are elevational views, partially in section, of another
embodiment of the device at various stages during a cutting or grasping
operation.
FIGS. 8-5A to 8-5E illustrate an embodiment of a device in accordance with
this invention in which the end portions and body portions of the elongate
elements are integral and are moved by a rotational actuator made of a
material other than a pseudoelastic material.
FIGS. 8-6A to 8-6E illustrate representative cross sections of end portions
of the elements adapted to grasp or cut an object.
FIGS. 8-7A to 3-7E illustrate various actuating means which function to
cause the elements to splay apart and come together and, optionally,
rotate the elements, and/or withdraw the elements into or out of the
hollow component.
FIG. 8--8 illustrates an embodiment of the device of this invention in
which the end portions are curved when at least partially unconstrained
and pinned together pivotally at their tips.
FIG. 8-9 demonstrates a method of using a grasping device of this
invention.
FIGS. 8-10A to 8-10C illustrate an embodiment of the device of this
invention in which the elements are splayed and in which the body portions
of the elements are bent when the elements are unconstrained.
FIGS. 8-11A and 8-11B illustrate a device of this invention in which the
elements have end portions beyond a pivot point, and in which the body
portions of the elements are of pseudoelastic material and when
unconstrained are bent to splay the end portions and position them at a
desired angle with respect to the hollow component. The body portions act
as actuating means to open and close the end portions of the elements to
dissect, grasp and/or cut an object.
FIG. 8-12 illustrates a device similar to the device in FIG. 8-11B, but in
which the body portions of the elements are made of a pseudoelastic
material and have a bend of about 90.degree..
FIG. 8-13 illustrates another device in accordance with this invention.
The device of the eighth form this invention comprises a hollow elongate
component and two elongate elements. Preferably, the hollow component is
tubular. This has the advantage that the device can be operated remotely.
The material of the hollow component may be polymeric. It may be flexible
or rigid. If made of polymeric material, the material may be reinforced,
for example, with fibers, to enable it to withstand the forces exerted on
it by the elements while they are constrained within and deformed by the
component. A suitable polymeric material for the component is, for
example, polytetrafluoroethylene, reinforced with braided fibers.
Alternatively, the material of the hollow component may be metallic, for
example stainless steel. A preferred hollow component is an elongate tube,
preferably formed from stainless steel. The elongate hollow component can
be, for example, a tubular housing, cannula, catheter or sheath.
The hollow component may be circular in cross-section which can have the
advantage that it permits deformation of the elements substantially
uniformly in all directions. Other cross-sections may be preferable in
some situations. For example, it can be advantageous to use a hollow
component which has the same shape in cross-section as the elements which
are received within it, to minimize twisting of the elements relative to
one another.
Preferably, the elements are at least partially formed from a pseudoelastic
material, such as a shape memory alloy that exhibits pseudoelasticity.
Shape memory alloys which exhibit superelasticity, are especially
preferred. As explained above as a superelastic shape memory alloy is
increasingly deformed from its unconstrained shape, some of its austenitic
phase changes Into stress-induced-martensite and the stress/strain curve
presents a plateau during this phase change. This means that while the
alloy undergoes this phase change, it can deform greatly with only minimal
increases in loading. Therefore, cutting, dissecting and grasping elements
comprising superelastic shape memory alloys have a built-in safety
feature. These elements can be designed (using appropriately treated
alloys and appropriate dimensions) such that when they are loaded beyond a
certain amount, the elements will tend to deform with a concomitant
austenite to stress-induced-martensite phase change, instead of merely
presenting a greater resistance with limited deformation to the load,
which is seen with conventional metals.
While the alloy that is used in the devices of this eighth form of the
invention may exhibit either linear pseudoelasticity or superelasticity
(which is sometimes referred to as non-linear pseudoelasticity), or
pseudoelasticity of an intermediate type, it is generally preferred that
it exhibit superelasticity because of the large amount of deformation that
is available without the onset of plasticity. Any of the materials
described hereinbefore including elastically deformable materials,
pseudoelastic materials, superelastic materials, and shape memory alloys
can be used in this eighth form of the invention.
The device according to the eighth form of the invention has the advantage
that, by use of elongate elements formed at least partially from a
pseudoelastic material which can be deformed, it can be used in
applications in which there is a limited amount of space. Furthermore, the
device can be operated remotely or at an angle more conveniently than many
previously used devices.
In certain embodiments of the invention, at least one of the end portions
of the elongate elements is formed from a pseudoelastic material,
preferably a pseudoelastic shape memory alloy, and that end portion may
have a curved configuration when not constrained and can be deformed into
a straightened configuration when within a constraint, such as a hollow
component. The term "straightened configuration" means that the
configuration of the element is straighter when deformed than it is when
not deformed. This may be used in dissection (the separation of tissues).
When the end portion of the element (or end portions of the elements if
both are of a pseudoelastic material) is extruded from the hollow
component it is no longer constrained and reverts or recovers to splay
away from the other element. When the end portion is withdrawn back into
the hollow component, or the hollow component is drawn over the end
portion, it moves toward the other end portion grasping or cutting any
object placed between them.
In some embodiments of the invention, the end portions of the elongate
elements are formed from a pseudoelastic material, preferably a
pseudoelastic shape memory alloy, and are deformed into a straightened
configuration when within the hollow component and curve at an angle to
the end of the component when extended therefrom.
In certain other embodiments the end portions of the elongate elements are
formed from a pseudoelastic material, preferably a pseudoelastic shape
memory alloy, and are deformed into a curved configuration when within the
component and are substantially straight when extruded from the component.
In still other embodiments, the body portion of one or both of the elongate
elements is formed from a pseudoelastic material, preferably a
pseudoelastic shape memory alloy, and the body portion of the element
becomes curved on exiting the component, thereby splaying the end portion
away from the other end portion.
In any embodiment, an actuating means, which may be formed from a
pseudoelastic material, preferably a pseudoelastic shape memory alloy, can
be provided to splay the end portions apart from one another and/or to
move them toward one another. In such embodiments, it is not necessary for
the elongate elements to be formed from a pseudoelastic material.
In summarizing, at least a portion of at least one, preferably each, of the
elongate elements is formed from a pseudoelastic material, preferably a
pseudoelastic shape memory alloy. The use of a shape memory alloy which
exhibits pseudoelasticity has the advantage that the amount of elastic
deformation that is available is large compared with that available from
many other materials. In certain preferred embodiments, the end portion of
one or both of the elements is formed from a pseudoelastic shape memory
alloy. In other embodiments, a section of the body portion of one or both
of the elements is formed from a pseudoelastic shape memory alloy. The
large amount of elastic deformation of the elements allows the device to
be used to dissect, grasp and/or cut large objects, while ensuring also
that the device has a small transverse dimension when the elements are
deformed inwardly, allowing the device to pass through small spaces.
The end and body portions of the elongate elements may be formed from the
same material, for example, both may be formed from a shape memory alloy,
for convenience. Frequently, however, it may be preferable to use
different materials because of the different functions that the end and
body portions might have to serve. For example, the end portions may be of
stainless steel or the like to provide a sharp cutting edge or a cutting
edge of stainless steel may be provided on a part of end portions formed
from a sharp memory alloy. The cross-sections of the end and body portions
will generally be different, although this need not necessarily be the
case. For example, the end portions may be rectangular to present a
grasping surface or triangular to present a cutting surface, and the body
portions may be rectangular for rigidity.
In some embodiments, the end portions of the elongate elements are
pivotally connected to one another towards their free ends. This minimizes
the possibility of an object becoming dislocated from the device before it
is grasped or cut. The device may then be used to move an object once it
has been positioned between the elements. This can also be achieved when
the elements are not joined together at their free ends, but with less
control in some situations. When the elements are not connected directly
at their free ends, they may be connected by a flexible component which
extends between the end portions of the elements so as, together with the
end portions of the elements, to form a closed loop. Leaving the elements
unattached at their free ends can facilitate positioning the device so
that the object is located between the elements. The tips of the free ends
may be blunt, especially when the elements are not attached at their free
ends. Alternatively, the free ends may be pointed to facilitate
dissection, for example.
The end portions of the elongate elements may be provided with a cutting
edge of a material other than a shape memory alloy. The cutting edge may
be inlaid in the end portion or can extend from the end portion of the
device.
Preferably the body portions of the elongate elements are attached to one
another. This can facilitate manipulation of the two elements. For
example, the elements may be attached to one another by adhesive material
or by fasteners such as screws or rivets, or the elements may be formed as
a single body of material. Alternatively, the elements may be attached to
an elongate member by which they are moved longitudinally relative to the
hollow component. For example, such a member may be hollow, at least at
its end, and the elements may be received within the member.
The elongate elements may be symmetrical when they are splayed outwardly
apart, and preferably also when deformed inwardly. However, for some
applications, it might be appropriate for the elements not to be
symmetrical, or for the elements not to be deformed symmetrically (for
example only one of the elements might be deformed), or both.
The cutting surfaces of the elongate elements may abut one another in the
manner of wire cutters, or they may cross one another in the manner of
shears. The grasping surfaces of the elements may abut one another and be
sufficiently blunt to avoid cutting the object to be grasped.
Alternatively, the grasping surfaces need not be configured so as to
contact each other in the manner of cutting devices. The object being
grasped need merely be entrapped between the end portions of the elements.
The grasping surfaces may be ridged or contain protuberances to assist in
grasping the object.
In certain embodiments, an object may be grasped or cut using the device of
the invention by ringing the device and the object together while the
elongate elements are positioned at least partially within the component,
and by then moving the hollow component and the elements longitudinally
relative to one another, so that the end portions of the elements extend
from the object and become splayed outwardly. This action can be used to
spread or dissect surrounding material from the object, if desired, to
isolate the object. The object can Then be positioned between the elements
to be grasped or cut in accordance with the method described above.
In other embodiments, the device is provided with means for actuating the
end portions of the elongate elements, which are not necessarily formed
from a pseudoelastic. Illustrative actuating means are described more
fully below with reference to the drawings and include rack and pinion
means, pin and slot means, four-bar linkages and the like. In certain
embodiments, the actuating means may be formed of a pseudoelastic
material. The actuating means may permit the elements to be rotated. The
actuating means may also provide suitable means for irrigating the
elements, or conduct electrical current to one or both of the elements, if
desired.
The device will be particularly useful in applications in which access to
an object to be dissected, cut or grasped is restricted, for example in
medical applications in which the object to be dissected, cut or grasped
is a part of a human or animal body. In these applications, the elongate
elements may be positioned in the body by means of a hollow component in
the from of a cannula, catheter or sheath introduced, for example, through
an opening into a body cavity.
The device may be arranged so that the axis on which the elements dissect,
cut and/or grasp the object is not coaxial with the axis of at least a
significant portion of the hollow component. This may be arranged, for
example, by providing the elongate elements with a suitable bend. The
elements may be deformed from their bent configuration towards their
straight configuration, and held in the straight configuration, by the
hollow component while they are within it. Alternatively, it may be
arranged by use of a hollow component which is bent towards the end from
which the elements extend.
The device may also be useful in the assembly of mechanical, electrical or
other equipment, for example by means of robots.
Turning now to the drawings, FIGS. 8-1 and 8-2 show a cutting or grasping
device which comprises two elongate elements 1 and 3, each having a body
portion 5 and an end portion 7. The end portions are joined together
pivotally at their free ends by a pin 9. The end portions preferably have
a triangular cross-section, where the apex of the triangle provides a
cutting surface 10. Alternatively, any flat cross-sectional area may
present a grasping surface. Other possible cross-sectional areas are
illustrated in FIGS. 8-6A to 8-6E.
The elongate elements are preferably formed from a pseudoelastic material,
preferably a shape memory alloy which has been treated so that it exhibits
pseudoelasticity in the temperature range between ambient temperature and
a temperature above body temperature.
Elongate elements 1 and 3 are located within an elongate housing 11 within
which they can slide longitudinally, the housing preferably being a stiff
tubular sheath. The elongate elements can be extended beyond the end of
housing 11 by longitudinally moving them relative to housing 11 via any
suitable manually operated mechanism.
FIG. 8-2 shows the cross-sectional configurations of elongate elements 1
and 3 at positions A--A, B--B, and C--C of FIG. 8-1, which illustrates the
elongate elements splayed apart.
FIG. 8-3A shows a cutting device with elongate elements 1 and 3 restricted
completely within housing 11, which holds the elongate elements in a
deformed configuration inwardly towards one another. The housing is
positioned as desired relative to an object to be cut (or dissected or
grasped) while the elongate elements are in this configuration. Once so
positioned, the end portions 7 of the elongate elements are caused to
extend from the housing, by relative movement of the elements and the
housing. Once released from the transverse constraint imposed by the
housing, end portions 7 of the elements splay outwardly apart, as shown in
FIG. 8-3B, allowing an object 15 to be positioned between them, as shown
in FIG. 8-3C.
Object 15 is caused to engage the surfaces 10 of elongate elements 1 and 3.
Relative longitudinal movement of the elongate elements and the housing
will force at least parts of the elongate elements together, thereby
grasping or cutting the object, as shown in FIGS. 8-3D and 8-3E. If
desired, object 15 can be moved by holding the housing and moving the
elongate elements. If it is desired not to move object 15, the elongate
elements are held fixed and the housing is moved. The elongate elements
can be retracted into the housing for removal of the device from the site
of the dissecting, cutting and/or cutting operation.
The end portions 7 (or any other portion, as desired) of elongate elements
1 and 3 may represent sections of spherical surfaces to facilitate the
splaying and closing. End portions 7 may be used to grasp, instead of
cutting, tissues. The grasping function would be facilitated if end
portions 7 do not have cutting surfaces 10, and if end portions 7 are not
fully retracted back into housing 11. Furthermore, the splaying action of
elongate elements 1 and 3 may be utilized to separate tissues for
dissection.
FIG. 8-4 shows a device which comprises two elongate elements 21 and 23
that are preferably formed from a pseudoelastic material and more
preferably a shape memory alloy which has been treated so that it exhibits
superelastic behavior. The elements can slide longitudinally within a
tubular housing 25. FIG. 8-4A shows the device with the elongate elements
21 and 23 positioned almost entirely within the tubular housing 25.
Housing 25 constrains elongate elements 21 and 23 in straightened and
deformed shapes.
As elongate elements 21 and 23 are moved longitudinally relative to housing
25, the elongate elements extend from the end of housing 25, as shown in
FIGS. 8-4B and 8-4C. As they extend from the end of housing 25, the
elongate elements become unconstrained and recover toward their preset
curved shapes pseudoelastically. They pseudoelastically splay outwardly so
that they can receive an object 27 between them or, alternatively, be used
to dissect surrounding material. The elongate elements may be
interconnected indirectly towards their free ends 29 by a flexible
component, such as a piece of wire 31, which helps to prevent dislocation
of object 27 from between the elongate elements. Object 27 is cut or
grasped by relative movement between housing 25 and the elongate elements,
such that the elongate elements become constrained within the housing,
generally as described above with reference to FIG. 8-3. The splaying
action of elongate elements 21 and 23 may also be utilized to separate
tissues for dissection. Elongate elements 21 and 23 may curve out of the
plane of the paper.
FIG. 8-5A illustrates an embodiment of the invention in which elongate
elements 51 and 52 are substantially planar and straight in their
unconstrained shapes, but are located in a plane which deviates by an
angle .phi. from a plane which includes the axis x--x of a hollow tube 53.
In this embodiment, elongate elements 51 and 52 are attached to outer tube
53 and inner tube 55, respectively, as shown in FIG. 8-5B. The proximal
end (i.e., the end opposite the elongate element 52) of inner tube 55 is
provided with a groove 58, and inner tube 55 is positioned within outer
tube 53. The proximal end of outer tube 53 is provided with a groove 59,
which extends in a direction opposite to groove 58 of inner tube 55.
Plunger 60 is provided with a peg 60a. The plunger may be positioned at
the proximal end of the tubes. The proximal ends 58p and 59p of grooves 58
and 59, respectively, are positioned such that they overlap and are
engaged by peg 60a. When peg 60a engages proximal ends 58p and 59p of
grooves 58 and 59, elongate elements 51 and 52 are preferably splayed
apart in the plane defined by their respective flat surfaces. When plunger
60 is pushed into inner tube 55 in a distal direction toward the elongate
elements, peg 60a engages grooves 58 and 59, causing tubes 53 and 55, and
thereby the elongate elements 51 and 52, to rotate in opposite directions.
Preferentially, this rotation would cause the elongate elements to rotate
into a more overlapped configuration. The elongate elements can thereby
grasp an object placed between them. If the elongate elements have cutting
edges, they could thereby cut an object placed between them. When plunger
60 is withdrawn from inner tube 55 again, peg 60a could cause tubes 53 and
55 to rotate such that elongate elements 51 and 52 splay apart from their
overlapped configuration. Elongate elements 51 and 52 could thereby be
used to separate tissues for dissection.
With respect to this embodiment, it should be noted that the angle .phi.
between elongate elements 51 and 52 and tubes 53 and 55 can be any number
of degrees desired. In addition, the elongate elements may be curved, not
only within the plane generally described by their plane of motion, but
also out of the plane generally described by their plane of motion.
Furthermore, there may be more than one peg on plunger 60. Correspondingly
there would be additional grooves (or slots) in tubes 53 and 55. The
grooves may be spiralled, and longer, such that elongate elements 51 and
52 could be caused to rotate in both directions of their overlapped
position in one stroke of plunger 60. The grooves may also be located
anywhere along the lengths of tubes 53 and 55. Consequently, peg 60a may
be appropriately located anywhere along plunder 60. Finally, grooves 58
and 59 could be made configured such that elongate elements 51 and 52
could be brought to their overlapped configuration by withdrawing plunger
60 in a proximal direction away from the elongate elements.
FIG. 8-5C shows one method of the attachment of elongate elements 51 and 52
onto inner and outer tubes 53 and 55, respectively. Elongate element 52 is
provided with aperture 63 which fits over stem 64, which is integral with
or is secured to the distal end of inner tube 55. The length of stem 64 is
equal to or less than the thickness of elongate element 52. The
cross-sectional shapes of aperture 63 and stem 64 are preferably
noncircular, and they may, for example, be square, serrated, notched, etc.
Screw 65 and washer 66 fasten elongate element 52 to inner tube 55. Washer
66 may have a beveled side to accommodate the angle .phi. between the axis
x--x of inner tube 55 (and tube 53) and the plane of elongate elements 51
and 52 as shown in FIG. 8-5C. The distal face of tube 55 and the distal
face of stem 64 should also be slanted (not shown) at f relative to the
axis x--x of tube 55.
Elongate element 51 is provided with an aperture 68 which fits over stem
69, which is integral with or is secured to the distal end of outer tube
53. The length of stem 69 is preferably slightly greater than the
thickness of elongate element 51, so that rotation of elongate element 51
relative to elongate element 52 is not hindered. The cross-sectional
shapes of aperture 68 and stem 69 are preferably noncircular, and they
may, for example, be square, serrated, notched, etc. The distal face of
tube 53 and the distal face of stem 69 should be slanted (not shown) at an
angle f relative to the axis x--x of tube 53.
Inner tube 55, with attached elongate element 52, fits into outer tube 53.
Elongate element 51 will be captured between the base of stem 69 and
elongate element 52. Outer tube 53, with inner tube 55 contained therein,
and elongate elements 51 and 52 attached, can be inserted into a sheath
61. As shown in FIG. 8-5D, when elongate elements 51 and 52 are drawn into
sheath 61 (shown in cross-section), they will be deformed in a direction
more parallel to axis x--x. This deformation will be facilitated if
elongate elements 51 and 52 are transversely curved along their
longitudinal dimensions (i.e., trough shaped). Also, if the outer diameter
of tube 53 is only slightly smaller than the inner diameter of sheath 61,
the circumferences of elongate elements 51 and 52 along portions 81 and 83
(i.e., the circumferences of elongate elements 51 and 52 around their
respective apertures 68 and 63, except for their longitudinally extended
portions), should preferably not extend beyond the outer diameter of outer
tube 53. When outer tube 53 is extended distally beyond the end of sheath
61, elongate elements 51 and 52 will no longer be constrained, and they
will elastically recover their preset shapes again. This deformation and
shape recovery is enhanced if the elongate elements are made of a
pseudoelastic shape memory alloy.
FIG. 8-5E is a bottom view of a possible embodiment of washer 66.
Projection 62 has an outer diameter which is equal to or smaller than the
outer diameter of outer tube 53. The surface of projection 62, which holds
elongate element 52, may be rough, or it may even have teeth or
protrusions, in order to obtain a better grip on elongate element 52.
Projection 62 preferably encompasses less than half of the circumferential
arc of washer 66. The remaining circumference of washer 66 has a outer
diameter which is equal to or smaller than the maximum diameter of the
head of screw 65. The head of screw 65 preferably has a diameter which is
equal to or less than the smallest diametral dimension of stem 64. As
shown in FIG. 8-5D, projection 62 covers the back end of elongate element
52. In this manner, elongate element 52, and secondarily, elongate element
51, can be given as much bending length as possible when they are both
constrained within sheath 61. The sides 33 and 34 of projection 62 are
preferably parallel to axis y--y, where axis y--y is perpendicular to the
longitudinal dimension of elongate element 52 and is perpendicular to the
axis of symmetry of washer 66. This will permit ready bending of elongate
element 52 along a zone which is perpendicular to its longitudinal
dimension.
There may be any suitable means between outer tube 53 and inner tube 55 to
prevent plunger 60 from pushing inner tube 55 out of outer 53 tube when
plunger 60 is pushed in a distal direction in inner tube 55. In addition,
there may be any suitable means between outer tube 53 and sheath 61, so
that outer tube 53 can not be completely pushed out of sheath 61 once
elongate elements 51 and 52 are adequately extended out of sheath 61 and
plunger 60 is used to cause rotation of elongate elements 51 and 52.
Plunger 60 can be pushed relative to sheath 61 and tubes 53 and 55 by any
suitable manually operated mechanism. Examples of manually operated
mechanisms include sliders, pistol grip handles, scissors handles, and
syringe-plunger arrangements.
An alternate version of the embodiment of FIG. 8-5 would have a stiff
central rod slid along an inner longitudinal bore in the plunger. In this
case, the elongate elements would be attached to their respective tubes
along one side of the wall of each tube, e.g. by welding or by
longitudinally slitting the walls instead of being herd by a screw. The
central rod could then be used to straighten the elongate elements
(assuming the elongate elements do not have any apertures) and deform them
to be more in line with the axis of the tubes.
While most of the specific embodiments are directed to cutting devices, it
is to be understood that blunt edges can replace the cutting edges in any
of the embodiments. Illustrative blunt and cutting edges are shown in
FIGS. 8-6A-E. The cutting and grasping edges may be integral with the
elements or may be formed separately and/or of different materials and
attached thereto. FIG. 8-6A illustrates grasping surfaces 71 and 72.
Surfaces 71 and 72 may be flat or they may contain ridges, protrusions or
the like to aid in gripping an object. FIG. 8-6B illustrates shearing
cutting edges 73 and 74 which cut an object by a shearing action. FIG.
8-6C illustrates another pair of edges for cutting. In FIG. 8-6C, surface
75 is flat, while edge 76 provides a sharp edge for cutting an object.
FIG. 8-6D illustrates cutting edges 77 and 78. Sharp edges 77 and 78 of
the triangular cross-sections meet to permit cutting. FIG. 8-6E
illustrates cutting edges 80 and 82, which are at any desired angles
.alpha. and .beta. relative to the direction of opening and closing of the
elongate elements. In all of these embodiments, as well as in all of the
embodiments described herein, the cutting edges or gripping surfaces could
be made of any material such as steel, diamond, plastic, etc., which is
attached to the elongate elements.
In any of the embodiments, dissection could be performed by providing any
suitable edge opposite edges 71-78 and 80 and 82 of FIGS. 8-6A-E.
FIGS. 8-7A, B and C illustrate several different means of actuating
elongate elements. In FIG. 8-7A, the body portions of elongate elements
150 and 151 are joined together at pivot 152. Also joined at pivot 152 is
one end of a linkage composed of four links 153, 154, 155, and 156, which
are pivotally connected to each other. Elongate elements 150 and 151 are
preferably rigidly attached to links 153 and 154, respectively.
Alternatively, links 153 and 154 may merely represent extensions of
elongate elements 150 and 151, respectively. Pivot 152 is preferably fixed
to a cannula 159. The pivot 157 at the other end of the linkage is joined
to rod 158. When rod 158 is pushed in direction 301, pivot 157 is pushed
closer to pivot 152. This will cause elongate elements 150 and 151 to
splay apart. Since the transverse dimension of linkage 153, 154, 155, and
156 which is perpendicular to rod 158 becomes larger as pivot 157
approaches pivot 152, slots 160 and 161 may be provided in cannula 159 to
permit pivot 157 to approach closer to pivot 152 if the transverse
dimension of cannula 159 is small. Rod 158 may be pushed (or pulled)
relative to cannula 159 by any suitable manually operated mechanism.
Examples of manually operated mechanisms include sliders, pistol grip
handles, scissors handles, and syringe-plunger arrangements.
Elongate elements 150 and 151 may be constrained in deformed and
straightened shapes within a sheath 162. This will permit compact and
relatively atraumatic entry into a body. Rod 158 can then be pushed
axially in direction 301 within sheath 162. The linkage 153, 154, 155, and
156 will partially extend through slots 160 and 161 in cannula 159, but
the inner surface of sheath 162 will prevent pivot 157 from fully
approaching pivot 152. Therefore, cannula 159 will be forced to move in
direction 301, and elongate elements 150 and 151 will extend from the end
of sheath 162 in direction 301. In their extended position, elongate
elements 150 and 151 will not be constrained, and they may recover toward
their preset shape, which may, for example, be curved out of the plane of
the paper. Slots 163 and 164 are provided in sheath 162 to permit rod 158
to push pivot 157 fully toward pivot 152 in order to fully splay elongate
elements 150 and 151 apart. Slots 163 and 164 in sheath 162 may be made to
overlap slots 160 and 161 in cannula 159 by simply extending cannula 159
far enough within sheath 162, or by extending cannula 159 far enough
within sheath 162 and then rotating sheath 162 relative to cannula 159 to
allow the respective slots to coincide. Rod 158 may then be used to splay
or increasingly overlap elongate elements 150 and 151 as desired.
Rod 158 can be moved in direction 302 so that pivot 157 is moved as far
away as possible from pivot 152. This will cause elongate elements 150 and
151 to be in their most overlapped configuration. Moving rod 158 further
in direction 302 relative to sheath 162 will cause cannula 159 to slide in
direction 302, and will cause elements 150 and 151 to be drawn into
straightened (i.e. non-curved) shapes within sheath 162. This will permit
the entire assembly to be withdrawn from the body in a compact and
relatively atraumatic fashion.
The passive (reference) member of the manually operated mechanism would
preferably be mounted to sheath 162. In this fashion, the extension and
withdrawal of elongate elements 150 and 151 from or into sheath 162 can be
accomplished by utilizing an expanded stroke of the same manually operated
mechanism which is used to splay or increasingly overlap elongate elements
150 and 151. In this case, a means must be provided to prevent cannula 159
from sliding beyond a certain location within sheath 162 in direction 301.
Also, a means may be provided to minimize relative motion between cannula
159 and sheath 162 while the linkage is being used to repeatedly move
elongate elements 150 and 151 toward their splayed or overlapped
configurations. Furthermore, the manually operated mechanism would
preferably permit axial rotation of the entire assembly of sheath 162 and
its contents relative to the manually operated mechanism, so that elongate
elements 150 and 151 can be oriented in any desired direction relative to
the manually operated mechanism,
In the configuration illustrated in FIG. 8-7A, it will be noted that
movement of rod 158 in direction 301 will tend to splay elongate elements
150 and 151 apart. As described above, one method of minimizing this
splaying before the device is in the correct location is to create slots
in specific locations of sheath 162. In an alternative method, links 156
and 155 are shorter than links 153 and 154, and pivot 157 is already
positioned as close as possible to pivot 152 during placement of the
device into a body. (In this configuration, links 155 and 156 would
overlap links 153 and 154, respectively.) Moving rod 158 in direction 301
will then urge elongate elements 150 and 151 toward their overlapped
configuration, even though the elongate elements can be extended beyond
the end of sheath 162 by motion in direction 301 when the sheath is held
fixed. Elongate elements 150 and 151 can then be splayed apart by moving
rod 158 in direction 302, When the device is to be withdrawn from a body,
rod 158 is moved further in direction 302, so that pivot 157 is as far as
possible from pivot 152, where the configuration shown in FIG. 8-7A would
be an intermediate position. Elongate elements 150 and 151 will thereby be
urged back toward their overlapped configuration. Moving rod 158 even
further in direction 302, relative to sheath 162, will permit withdrawal
of elongate elements 150 and 151 into sheath 162.
FIG. 8-7B shows an embodiment in which elongate elements 150 and 151 have a
pivot 165 and body portions 166 and 167, respectively. Body portions 166
and 167 have slots 168 and 169, respectively. A rod 190 has a peg 191
which is oriented to slideably engage slots 168 and 169. Pivot 165 is
fixed to the cannula 192, and slots 168 and 169 are preferably oriented so
that motion of rod 190 in direction 310 will urge elongate elements 150
and 151 toward their overlapped configuration, and motion of rod 190 in
direction 320 will splay elongate elements 150 and 151 apart. However,
slots 168 and 169 could be curved such that extreme motion of rod 190 in
direction 320 will again bring elongate elements 150 and 151 to their
overlapped configuration. Cannula 192 may be substantially the same as
cannula 159 shown in FIG. 8-7A. In addition, a sheath 193, which may
substantially be the same as sheath 162 shown in FIG. 8-7A, can be
utilized. The function and use of the embodiment shown in FIG. 8-7B is
then substantially the same as the embodiment shown in FIG. 8-7A.
A variation of the embodiment illustrated in FIG. 8-7B would include
elongate elements in which the slots are placed distal to the pivot point
between the elongate elements. (That is, the slots are located between the
pivot point and the tips of the elongate elements). Body portions 166 and
167 as shown in FIG. 8-7B, and slots 160, 161, 163, and 164 as shown in
FIG. 8-7A may then not be necessary. However, the actuating rod (such as
rod 190 shown in FIG. 8-7B), would have to be designed so that it does not
interfere with the pivot point between the elongate elements.
FIG. 8-7C shows another embodiment in which the elongate elements 150 and
151 may be made to splay apart or increasingly overlap each other.
Elongate elements 150 and 151 are hinged at pivot 170, which is preferably
fixed to a cannula 176. Surrounding pivot 170, elongate elements 150 and
151 each have a rounded body portion with teeth along edges 171 and 172,
respectively. The teeth engage the corresponding grooves located in jaws
173 and 174 of sliding member 175. The degree of splaying or overlapping
of elongate elements 150 and 151 may be limited by limiting the lengths of
edges 171 or 172 which are toothed. Additionally, or alternatively, the
degree of splaying or overlapping of elongate elements 150 and 151 may be
limited by limiting the lengths of the grooved zones in jaws 173 and 174.
Sliding member 175 is moved in direction 303 or 305 by any suitable
manually operated mechanism. Examples of manually operated mechanisms
include sliders, pistol grip handles, scissors handles, and
syringe-plunger arrangements. Elongate elements 150 and 151 are preferably
moved toward their overlapped configuration when sliding member 175 is
moved in direction 303 and moved toward their splayed apart configuration
when sliding member 175 is moved in direction 305 (not shown). However,
toothed edges 171 and 172 can be located on elongate elements 150 and 151
such that moving sliding member 175 in direction 303 moves elongate
elements 150 and 151 toward their splayed configuration and moving sliding
member 175 in direction 305 moves elongate elements 150 and 151 toward
their overlapped configuration.
Elongate elements 150 and 151 may be constrained in straightened shapes
within a sheath 178. This will permit compact and relatively atraumatic
entry into a body. Sliding member 175 can then be moved in direction 303
relative to sheath 178 in order to extend elongate elements 150 and 151
from the end of the sheath. In the preferred mode, this motion will also
tend to keep elongate elements 150 and 151 in their overlapped
configuration without splaying these elements apart in the wrong
direction. (As described above, toothed edges 171 and/or 172 and/or the
jaws 173 and/or 174 can be designed to prevent splaying in the wrong
direction). Elongate elements 150 and 151 can then be repeatedly moved
toward their splayed configuration or their overlapped configuration by
moving sliding member 175 in directions 305 or 303, respectively, and a
means may be provided to minimize relative motion between cannula 176 and
sheath 178 during this repetitive motion.
Elongate elements 150 and 151 can be withdrawn back inside sheath 178 by
forcibly moving sliding member 175 in direction 305 relative to sheath
178. In a preferred version (not shown) the end of sheath 178 would force
elongate elements 150 and 151 into their overlapped configuration, as well
as forcing elongate elements 150 and 151 into straightened shapes into
sheath 178 in order to permit the entire assembly to be withdrawn from a
body in a compact and relatively atraumatic fashion. Alternatively, sheath
178 can be extended over elongate elements 150 and 151 to straighten these
elements into sheath 178 and to permit the entire assembly to be withdrawn
from a body in a compact and relatively atraumatic fashion.
If a sheath 178 is utilized, it could be mounted to the passive (reference)
member of the manually operated mechanism. In this fashion, the extension
and withdrawal of elongate elements 150 and 151 from or into sheath 178
can be accomplished by utilizing an expanded stroke of the same manually
operated mechanism which is used to move sliding member 175 in order to
splay or increasingly overlap elongate elements 150 and 151. In addition,
in order to permit the elongate elements 150 and 151 to be oriented in any
desired direction relative to the manually operated mechanism, this
mechanism would preferably permit axial rotation of the entire assembly of
sheath 178 and its contents relative to the manually operated mechanism.
When elongate elements 150 and 151 are to be removed and replaced, it would
be advantageous to move cannula 176 far enough in direction 303 so that
pivot 170 is beyond the end of sheath 178. Then the pivot pin can be
removed, sliding member 175 can be extended in direction 303 beyond the
end of cannula 176, and elongate elements 150 and 151 can be simply slid
out of jaws 173 and 174 in a direction perpendicular to the longitudinal
axis of sliding member 175.
FIG. 8-7D shows how sliding member 175 could be configured around a pivot
fixing member 185, which has holes 181 and 182. Elongate elements 150 and
151 are rotatably mounted on a pin 180. The ends of pin 180 can be placed
into holes 181 and 182 when sheath 178 is pulled back in direction 400,
since the ends of sliding member 175 and the ends of pivot fixing member
185 can gently splay apart when they are not held within sheath 178. When
sheath 178 is moved back in direction 401, elongate elements 150 and 151
will be securely held when pin 180 is within sheath 178. The end of pivot
fixing member 185 which has holes 181 and 182 can be fork shaped.
Preferably a means is provided which minimizes motion of pivot fixing
member 185 relative to sheath 178 when sliding member 175 is utilized to
repeatedly move elongate elements 150 and 151 toward their splayed or
overlapped configurations. FIG. 8-7E shows the device before sheath 178 is
pulled back to permit insertion of elongate elements 150 and 151. In this
configuration, pin 180 is preferably longer that the dimension between the
two fork ends of pivot fixing member 185, so that pin 180 is firmly locked
into place.
In the embodiments described for FIGS. 8-7A, B, C, and D, the elongate
elements are preferably made of a pseudoelastic material, preferably a
pseudoelastic shape memory alloy. The unconstrained shapes may be curved
in directions away from the general planes of the body portions of the
elongate elements (e.g. out of the plane of the paper). Also, in any of
the embodiments described for FIGS. 8-7A, B, C, and D, the elongate
elements can be used for cutting, grasping, and/or dissecting tissues. The
end portions of the elongate elements can be fashioned appropriately for
any of these functions, or separate appropriately designed parts may be
attached to the end portions of the elongate elements.
FIG. 8--8 shows a cutting device, similar to the device shown in FIG. 8-1,
with curved elongate elements 91 and 93 extended from a housing 92. This
permits the elongate elements to be both open for dissecting, cutting
and/or grasping and curved at an angle 94 away from axis 95 of housing 92.
Angle 94 is defined by the axis 95 of housing 92 and the straight line 96
which passes through the point of intersection of axis 95 with the distal
end of housing 92 and the pin 99. Angle 94 can be any desired angle, even
greater than 90 degrees, thus permitting dissecting, cutting and/or
grasping in a direction off axis 95. This provides access to difficult to
reach locations in the body. Elongate elements 91 and 93 are preferably
shaped so that they circumscribe spherical arcs which allow the elements
to engage each other and perform the cutting or grasping function, either
as they are retracted back into housing 92, or as housing 92 is extended
over the elongate elements. The portions of elongate elements 91 and 93
which enter housing 92 assume a less curved shape. Elements 91 and 93 may
be formed of a pseudoelastic material, preferably a pseudoelastic shape
memory alloy.
FIG. 8-9 shows a device in which elongate elements 102 and 106, preferably
made of a pseudoelastic material and more preferably a superelastic shape
memory alloy, are first held constrained in straightened and deformed
shapes inside a cannula 103. This permits compact placement into a body
through tissue incision or orifice 108. Elongate elements 102 and 106 are
then extended out of cannula 103 by moving elongate elements 102 and 106
in direction 501 relative to cannula 103. Since at least part of extended
elongate elements 102 and 106 are no longer constrained, they will splay
apart due to recovery of the pseudoelastic material into its preset curved
unconstrained shape. Cannula 103 can be then be extended onto elongate
elements 102 and 106 to force these elements to approach each other.
Alternatively, elongate elements 102 and 106 can be withdrawn back into
cannula 103 to force these elements to approach each other. In either
mode, the tips of elongate elements 102 and 106 can be used to grasp
tissue 107 or an object. The grasping function of elongate elements 102
and 106 can be enhanced by providing the end portions of these elements
with bends 104 and 105, teeth (not shown), or the like at their tips.
Elongate elements 102 and 106 may also be ribbed or toothed along their
entire lengths (not shown). The described mode of action may permit the
instrument to be used multiple times in each location.
In embodiments of the invention in which the elongate elements are made of
a pseudoelastic shape memory alloy, the large pseudoelastic deformation
(up to 11% or more) permits much wider splaying of elongate elements 102
and 106 over a much shorter distance 109 than would be possible with
conventional metals. This permits working in more confined spaces,
particularly in endoscopic or laparoscopic surgery. A variation of this
embodiment may include more than two elongate elements.
Shape memory alloys have a special feature which is beneficial for any of
the embodiments of this invention, but in particular for any of the
embodiments in which a grasping action is desired (especially in the
embodiment shown in FIG. 8-9). As a superelastic shape memory alloy is
increasingly deformed from its unloaded shape, some of its austenitic
phase changes into stress-induced-martensite. The stress strain curve
presents a plateau during this phase change. This means that while the
alloy undergoes this phase change, it can deform greatly with only minimal
increases in loading. Therefore, elongate elements comprising superelastic
shape memory alloys have a built-in safety feature. These elements can be
designed (using appropriately treated alloys and appropriate dimensions)
such that when they am loaded beyond a certain amount, the elements will
tend to deform with a concomitant austenite to stress-induced-martensite
phase change, instead of merely presenting a greater resistance with
limited deformation to the load, which is seen with conventional metals.
Just as the stress strain curves of shape memory alloys present a plateau
upon loading, they also present a plateau in the stress strain curve upon
unloading. Unloading occurs when an elongate element made of superelastic
shape memory alloy is permitted to revert from a significantly deformed
shape toward its original unstressed shape, Because of the plateau, such
an element can maintain an almost constant force during much of the
unloading cycle until just before it is completely unloaded. This feature
is especially useful for any grasper embodiment of this invention, because
it means that an object held between one or more elongate elements made of
a superelastic shape memory alloy can be gripped with nearly a constant
force despite decreases in the amount(s) of deformation of the element(s).
FIGS. 8-10A, B, and C illustrate three views of another embodiment. As
elongate elements 121 and 123 are extended outside the housing 120, they
splay outward causing end portions 122 and 124 to separate also. When
elongate elements 121 and 123 are partially withdrawn into housing 120,
they cause end portions 122 and 124 to approach each other. If elongate
elements 121 and 123 are further withdrawn into housing 120, the sections
121e and 123e of elongate elements 121 and 123 are forced to deform into
straightened shapes in order to pass into housing 120, thus causing the
direction of orientation of end portions 122 and 124 to approach the
direction of axis 126 of housing 120, and the angle 125 approaches zero
degrees (angle 125 is defined by axis 126 of housing 120 and the plane of
end portions 122 and 124). End portions 122 and 124 may also be fully or
partially withdrawn into housing 120, if desired. The straight
configuration permits easy placement and/or removal of the instrument into
or from a body in a compact and relatively atraumatic fashion. However,
with elongate elements 121 and 123 in a completely extended position,
angle 125 permits access to difficult to reach locations.
In the embodiments shown in FIGS. 8-10A, B, and C, the body portions of
elongate elements 121 and 123 are preferably made of a pseudoelastic
material and more preferably a superelastic shape memory alloy.
Alternatively, sections 121e and 123e may be the only parts of elongate
elements 121 and 123 which are made of a pseudoelastic material. End
portions 122 and 124 may also be made of a pseudoelastic material, but
they could be made of any suitable material, even if elements 121 and 123
are made at least in part of a pseudoelastic material. End portions 122
and 124 may have a cutting function or a grasping function. Also, end
portions 122 and 124 may be curved. They may also be used to separate
(dissect) tissues. The described mode of action may permit the instrument
to be used multiple times in each location.
FIGS. 8-11A and 8-11B show embodiments similar to the embodiments shown in
FIGS. 8-1 and 8--8, respectively. In FIGS. 8-11A and 8-11B, the elongate
elements 131 and 133 extend beyond the pin 139 in order to provide end
portions 135 and 134. End portions 135 and 134 may be unitary extensions
of elongate elements 131 and 133 or they may be separate portions bolted
or attached to elongate elements 131 and 133. The action of withdrawing
elongate elements 131 and 133 into housing 111 closes and deforms body
portions 117 and 116, and the scissor action is transmitted to end
portions 135 and 134. In this manner, the body portions of the elongate
elements act as the actuating means for the end portions of the elongate
elements. FIG. 8-11B illustrates a curved version of FIG. 8-11A. The angle
112 is defined by the axis 113 of housing 111 and the straight line 114
passing through the point of intersection of axis 113 with the distal end
of the housing and pin 139. Angle 112 can be any number of degrees, even
greater than 90 degrees, thus permitting dissection, cutting and/or
grasping in a direction off axis 113. This provides access to difficult to
reach locations within a body.
In the embodiments of FIGS. 8-11A and 8-11B, body portions 116 and 117 are
preferably made of a pseudoelastic material, preferably a superelastic
shape memory alloy. Alternatively, only end portions 134 and 135 may be
made of a pseudoelastic material, but these end portions could be made of
any suitable material, even if body portions 116 and 117 are made of a
pseudoelastic material. End portions 134 and 135 may have a cutting
function or a grasping function. They may also be used to separate and
dissect tissues. The described mode of action may permit the instrument to
be used multiple times in each location.
FIG. 8-12 illustrates another embodiment similar to the embodiment shown in
FIG. 8-11B. Body portions 141 and 143 of elongate elements 119 and 118 are
used to create both a scissors action through a pinned location 149 and
also to provide the ability to direct the scissor action at an angle of
about ninety degrees off the axis 148 of housing 140. Elongate elements
119 and 118 splay apart when they are outside of housing 140. As housing
140 is pushed over the body portions 141 and 143 in direction 144,
sections 141e and 143e move toward one another. This action in turn causes
the end portions 146 and 147 to approach each other in a scissor fashion
by pivoting around pin 149, which is substantially parallel to axis 148.
Because the relative movement of housing 140 in directions 144 and 145 is
perpendicular to end portions 146 and 147, the position of these end
portions is unchanged with respect to the tissue location. After end
portions 146 and 147 have closed, withdrawal of elongate elements 119 and
118 into housing 140 (or moving housing 140 in direction 144 relative to
elongate elements 119 and 118) causes sections 141 e and 143e to
straighten from their curved shapes. This permits end portions 146 and 147
to generally align with axis 148 of housing 140. End portions 146 and 147
may also be fully or partially withdrawn into housing 140, if desired. The
straight configuration permits easy placement and/or removal of the
instrument from a body in a compact and relatively atraumatic fashion.
In the embodiments of FIG. 8-12, body portions 141 and 143 of elongate
elements 119 and 118 are preferably made of a pseudoelastic material, more
preferably a superelastic shape memory alloy. Alternatively, sections 141e
and 143e may be the only parts of body portions 141 and 143 which are made
of pseudoelastic material. End portions 146 and 147 may also be made of
pseudoelastic material, but they could be made of any suitable material,
even if body portions 141 and 143 are made at least in pad of a
pseudoelastic material. End portions 146 and 147 may have a cutting
function or a grasping function. They may also be used to separate
(dissect) tissues. The described mode of action may permit the instrument
to be used multiple times in each location.
A variation of the embodiment shown in FIG. 8-12 would still have the bent
portions 141e and 143e, but would have end portions 146 and 147 in a plane
which is parallel to axis 148, so that pivot 149 is perpendicular to axis
148. In this embodiment, moving body portion 141 in direction 144 and/or
moving body portion 143 in direction 145 would tend to splay end portions
146 and 147 apart. Moving body portion 141 in direction 145 and/or moving
element 143 in direction 144 would tend to bring end portions 146 and 147
into a more overlapped configuration. In this manner, the body portions of
the elongate elements act as the actuating means for the end portions of
the elongate elements. In order to facilitate the requisite bending in
sections 141e and 143e, body portions 141 and 143 would preferably be
either round or made of flat material oriented in a plane perpendicular to
the plane of end portions 146 and 147. If body portions 141 and 143 are
made of flat material, they may include a 90 degree twist in the material
between sections 141e and 143e and end portions 146 and 147, respectively.
FIG. 8-13 shows a device of this invention in which the elongate elements
186 and 187 are bent, preferably about 90 degrees, relative to the
longitudinal axis of housing 188. The elongate elements are slid
longitudinally along the axis of housing 188 by means of any suitable
manually operated mechanism in order to separate end portions 183 and 184
from each other or to bring end portions 183 and 184 toward each other or
even in contact with each other. End portions 183 and 184 can have any
suitable surfaces in order to permit dissection, cutting, and/or grasping.
Elongate elements 186 and 187 are preferably made of a pseudoelastic
material, more preferably a superelastic shape memory alloy. This permits
the bent portions of elongate elements 186 and 187 to be deformed and
straightened so that the elongate elements can be withdrawn into housing
188. The straight configuration permits easy placement and/or removal of
the instrument from a body in a compact and relatively atraumatic fashion.
End portions 183 and 184 may be made of any suitable material, whether it
is pseudoelastic or not.
In any of the embodiments of this eighth form of the invention, preferably
both of the elongate elements are actuated by the manually operated
mechanism, so that dissection, cutting, and/or grasping is done by an
equal symmetrical motion of each elongate element. However, in some
situations, it may be desirable to have embodiments in which one elongate
element is moved more by the manually operated mechanism than the other
elongate element. In some cases, it may even be desired to have one
elongate element function as a stationary and thereby passive element,
where the manually operated mechanism only moves the other elongate
element.
In any of the embodiments of this eighth form of the invention, any
suitable manually operated mechanism may be utilized to move the elongate
elements. Possible mechanisms include sliders, pistol grip handles,
scissors handles, and syringe-plunger arrangements. In any of the
embodiments of this invention, it may be desirable to be able to axial
rotate the elongate elements relative to the manually operated mechanism,
so that the elongate elements can be pointed in a preferred direction
without having to rotate the manually operated mechanism itself. This
feature would enhance the comfort of using a device of this invention.
However, a means is preferably provided to prevent any undesired axial
rotation of the elongate elements relative to the manually operated
mechanism while the manually operated mechanism is being used to splay or
overlap the elongate elements.
In any of the embodiments of this invention, a suitable means may be
provided for passing a fluid (liquid or gas) through the device for
irrigation, aspiration, insufflation, etc. In any of the embodiments of
this invention, electricity may be passed to one or both end portion(s) of
the elongate element(s) for purposes of electrocautery or electrocutting.
In any of the embodiments of this invention, the tips (of the end portions)
of the elongate elements may be pointed or blunt. Pointed tips may
facilitate the use of the device of this invention in the separation
(dissection) of tissues, while blunt tips would minimize the risk of any
undesired trauma that the tips could inflict upon tissues.
While the invention has been described in connection with specific
embodiments thereof, those skilled in the art will recognize that various
modifications are possible within the principles described herein. Such
modifications, variations, uses, or adaptations of the invention,
including such departures from the present disclosure as come within known
or customary practice in the art, fall within the scope of the invention
and of the appended claims.
Top